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
if (traceId.isPresent()) {
                        threadContext.putHeader(Task.TRACE_ID, traceId.get());
                        threadContext.putTransient("parent_" + Task.TRACE_PARENT_HTTP_HEADER, traceparent);
                    }
                } else if (name.equals(Task.TRACE_STATE)) {
                    threadContext.putTransient("parent_" + Task.TRACE_STATE, distinctHeaderValues.get(0));
                } else {
                    threadContext.putHeader(name, String.join(",", distinctHeaderValues));
                }
            }
        }
    }
    public Map<String, ActionHandler<?, ?>> getActions() {
        return actions;
    }
    static Map<String, ActionHandler<?, ?>> setupActions(List<ActionPlugin> actionPlugins) {
        
        class ActionRegistry extends NamedRegistry<ActionHandler<?, ?>> {
            ActionRegistry() {
                super("action");
            }
            public void register(ActionHandler<?, ?> handler) {
                register(handler.getAction().name(), handler);
            }
            public <Request extends ActionRequest, Response extends ActionResponse> void register(
                ActionType<Response> action,
                Class<? extends TransportAction<Request, Response>> transportAction
            ) {
                register(new ActionHandler<>(action, transportAction));
            }