Seen in an exception stack trace: we are wrapping `ApiFilteringActionFilter` around itself many times, once per filtered action, so effectively every action is doing a linear scan of the filtered actions, implemented recursively. I'm pretty sure a hashmap would be more efficient, and would avoid inflating the stack so much too.

```
    at org.elasticsearch.action.support.TransportAction$RequestFilterChain.proceed(TransportAction.java:86) ~[elasticsearch-8.11.0-SNAPSHOT.jar:?]
    at org.elasticsearch.action.support.ActionFilter$Simple.apply(ActionFilter.java:53) ~[elasticsearch-8.11.0-SNAPSHOT.jar:?]
    at org.elasticsearch.action.support.TransportAction$RequestFilterChain.proceed(TransportAction.java:84) ~[elasticsearch-8.11.0-SNAPSHOT.jar:?]
    at org.elasticsearch.xpack.core.api.filtering.ApiFilteringActionFilter.apply(ApiFilteringActionFilter.java:53) ~[?:?]
    at org.elasticsearch.action.support.TransportAction$RequestFilterChain.proceed(TransportAction.java:84) ~[elasticsearch-8.11.0-SNAPSHOT.jar:?]
    at org.elasticsearch.xpack.core.api.filtering.ApiFilteringActionFilter.apply(ApiFilteringActionFilter.java:53) ~[?:?]
    at org.elasticsearch.action.support.TransportAction$RequestFilterChain.proceed(TransportAction.java:84) ~[elasticsearch-8.11.0-SNAPSHOT.jar:?]
    at org.elasticsearch.xpack.core.api.filtering.ApiFilteringActionFilter.apply(ApiFilteringActionFilter.java:53) ~[?:?]
    at org.elasticsearch.action.support.TransportAction$RequestFilterChain.proceed(TransportAction.java:84) ~[elasticsearch-8.11.0-SNAPSHOT.jar:?]
    at org.elasticsearch.xpack.core.api.filtering.ApiFilteringActionFilter.apply(ApiFilteringActionFilter.java:53) ~[?:?]
    at org.elasticsearch.action.support.TransportAction$RequestFilterChain.proceed(TransportAction.java:84) ~[elasticsearch-8.11.0-SNAPSHOT.jar:?]
    at org.elasticsearch.xpack.core.api.filtering.ApiFilteringActionFilter.apply(ApiFilteringActionFilter.java:53) ~[?:?]
    at org.elasticsearch.action.support.TransportAction$RequestFilterChain.proceed(TransportAction.java:84) ~[elasticsearch-8.11.0-SNAPSHOT.jar:?]
    at org.elasticsearch.xpack.core.api.filtering.ApiFilteringActionFilter.apply(ApiFilteringActionFilter.java:53) ~[?:?]
    at org.elasticsearch.action.support.TransportAction$RequestFilterChain.proceed(TransportAction.java:84) ~[elasticsearch-8.11.0-SNAPSHOT.jar:?]
    at org.elasticsearch.xpack.core.api.filtering.ApiFilteringActionFilter.apply(ApiFilteringActionFilter.java:53) ~[?:?]
    at org.elasticsearch.action.support.TransportAction$RequestFilterChain.proceed(TransportAction.java:84) ~[elasticsearch-8.11.0-SNAPSHOT.jar:?]
    at org.elasticsearch.xpack.core.api.filtering.ApiFilteringActionFilter.apply(ApiFilteringActionFilter.java:53) ~[?:?]
    at org.elasticsearch.action.support.TransportAction$RequestFilterChain.proceed(TransportAction.java:84) ~[elasticsearch-8.11.0-SNAPSHOT.jar:?]
    at org.elasticsearch.xpack.core.api.filtering.ApiFilteringActionFilter.apply(ApiFilteringActionFilter.java:53) ~[?:?]
    at org.elasticsearch.action.support.TransportAction$RequestFilterChain.proceed(TransportAction.java:84) ~[elasticsearch-8.11.0-SNAPSHOT.jar:?]
    at org.elasticsearch.xpack.core.api.filtering.ApiFilteringActionFilter.apply(ApiFilteringActionFilter.java:53) ~[?:?]
    at org.elasticsearch.action.support.TransportAction$RequestFilterChain.proceed(TransportAction.java:84) ~[elasticsearch-8.11.0-SNAPSHOT.jar:?]
    at org.elasticsearch.xpack.core.api.filtering.ApiFilteringActionFilter.apply(ApiFilteringActionFilter.java:53) ~[?:?]
    at org.elasticsearch.action.support.TransportAction$RequestFilterChain.proceed(TransportAction.java:84) ~[elasticsearch-8.11.0-SNAPSHOT.jar:?]
    at org.elasticsearch.xpack.core.api.filtering.ApiFilteringActionFilter.apply(ApiFilteringActionFilter.java:53) ~[?:?]
    at org.elasticsearch.action.support.TransportAction$RequestFilterChain.proceed(TransportAction.java:84) ~[elasticsearch-8.11.0-SNAPSHOT.jar:?]
    at co.elastic.elasticsearch.api.validation.PublicSettingsValidationActionFilter.apply(PublicSettingsValidationActionFilter.java:101) ~[?:?]
    at org.elasticsearch.action.support.TransportAction$RequestFilterChain.proceed(TransportAction.java:84) ~[elasticsearch-8.11.0-SNAPSHOT.jar:?]
    at org.elasticsearch.xpack.core.api.filtering.ApiFilteringActionFilter.apply(ApiFilteringActionFilter.java:53) ~[?:?]
    at org.elasticsearch.action.support.TransportAction$RequestFilterChain.proceed(TransportAction.java:84) ~[elasticsearch-8.11.0-SNAPSHOT.jar:?]
    at org.elasticsearch.xpack.core.api.filtering.ApiFilteringActionFilter.apply(ApiFilteringActionFilter.java:53) ~[?:?]
    at org.elasticsearch.action.support.TransportAction$RequestFilterChain.proceed(TransportAction.java:84) ~[elasticsearch-8.11.0-SNAPSHOT.jar:?]
    at org.elasticsearch.xpack.security.action.filter.SecurityActionFilter.lambda$applyInternal$3(SecurityActionFilter.java:163) ~[?:?]
    at org.elasticsearch.action.ActionListenerImplementations$DelegatingFailureActionListener.onResponse(ActionListenerImplementations.java:212) ~[elasticsearch-8.11.0-SNAPSHOT.jar:?]
```
server/src/main/java/org/elasticsearch/action/ActionModule.java
}
        }
        return result;
    }
    private static boolean isInternalPlugin(ActionPlugin plugin) {
        final String canonicalName = plugin.getClass().getCanonicalName();
        if (canonicalName == null) {
            return false;
        }
        return canonicalName.startsWith("org.elasticsearch.xpack.") || canonicalName.startsWith("co.elastic.elasticsearch.");
    }
    /**
     * Certain request header values need to be copied in the thread context under which request handlers are to be dispatched.
     * Careful that this method modifies the thread context. The thread context must be reinstated after the request handler
     * finishes and returns.
     */
    public void copyRequestHeadersToThreadContext(HttpPreRequest request, ThreadContext threadContext) {
        
        
        threadContext.putTransient(Task.TRACE_START_TIME, Instant.ofEpochMilli(System.currentTimeMillis()));
        for (final RestHeaderDefinition restHeader : headersToCopy) {
            final String name = restHeader.getName();
            final List<String> headerValues = request.getHeaders().get(name);
            if (headerValues != null && headerValues.isEmpty() == false) {
                final List<String> distinctHeaderValues = headerValues.stream().distinct().toList();
                if (restHeader.isMultiValueAllowed() == false && distinctHeaderValues.size() > 1) {
                    throw new IllegalArgumentException("multiple values for single-valued header [" + name + "].");
                } else if (name.equals(Task.TRACE_PARENT_HTTP_HEADER)) {
                    String traceparent = distinctHeaderValues.get(0);
                    Optional<String> traceId = RestUtils.extractTraceId(traceparent);