### 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
@Override
            public BootstrapCheckResult check(BootstrapContext context) {
                return BootstrapCheckResult.failure("error");
            }
            @Override
            public boolean alwaysEnforce() {
                return true;
            }
        };
        final NodeValidationException alwaysEnforced = expectThrows(
            NodeValidationException.class,
            () -> BootstrapChecks.check(emptyContext, randomBoolean(), Collections.singletonList(check))
        );
        assertThat(alwaysEnforced, hasToString(containsString("error")));
    }
    public void testDiscoveryConfiguredCheck() throws NodeValidationException {
        final List<BootstrapCheck> checks = Collections.singletonList(new BootstrapChecks.DiscoveryConfiguredCheck());
        final BootstrapContext zen2Context = createTestContext(
            Settings.builder().put(DiscoveryModule.DISCOVERY_TYPE_SETTING.getKey(), MULTI_NODE_DISCOVERY_TYPE).build(),
            Metadata.EMPTY_METADATA
        );
        
        BootstrapChecks.check(zen2Context, false, checks);
        
        BootstrapChecks.check(
            createTestContext(
                Settings.builder()
                    .put(DiscoveryModule.DISCOVERY_TYPE_SETTING.getKey(), randomFrom(SINGLE_NODE_DISCOVERY_TYPE, randomAlphaOfLength(5)))
                    .build(),
                Metadata.EMPTY_METADATA