### Description

The [bootstrap checks docs for 8.1](https://github.com/elastic/elasticsearch/blob/8.1/docs/reference/setup/bootstrap-checks.asciidoc#system-call-filter-check) still have a [section for disabling system call filters](https://www.elastic.co/guide/en/elasticsearch/reference/8.1/_system_call_filter_check.html) even though that setting was removed in 8.0 (#72848) and its removal is [listed in the breaking changes](https://www.elastic.co/guide/en/elastic-stack/8.0/elasticsearch-breaking-changes.html)


server/src/test/java/org/elasticsearch/bootstrap/BootstrapChecksTests.java
final BootstrapChecks.HeapSizeCheck check = new BootstrapChecks.HeapSizeCheck() {
            @Override
            long getInitialHeapSize() {
                return initialHeapSize.get();
            }
            @Override
            long getMaxHeapSize() {
                return maxHeapSize.get();
            }
            @Override
            boolean isMemoryLocked() {
                return isMemoryLocked;
            }
        };
        final NodeValidationException e = expectThrows(
            NodeValidationException.class,
            () -> BootstrapChecks.check(emptyContext, true, Collections.singletonList(check))
        );
        assertThat(
            e.getMessage(),
            containsString(
                "initial heap size [" + initialHeapSize.get() + "] " + "not equal to maximum heap size [" + maxHeapSize.get() + "]"
            )
        );
        final String memoryLockingMessage = "and prevents memory locking from locking the entire heap";
        final Matcher<String> memoryLockingMatcher;
        if (isMemoryLocked) {
            memoryLockingMatcher = containsString(memoryLockingMessage);
        } else {
            memoryLockingMatcher = not(containsString(memoryLockingMessage));