The test seems a bit flaky, since it has failed some times during the last 28 days. I cannot reproduce it locally.

**Build scan:**
https://gradle-enterprise.elastic.co/s/apnw3fyka43b2/tests/:x-pack:plugin:security:test/org.elasticsearch.xpack.security.authc.jwt.JwtRealmAuthenticateTests/testJwkSetUpdates

**Reproduction line:**
`./gradlew ':x-pack:plugin:security:test' --tests "org.elasticsearch.xpack.security.authc.jwt.JwtRealmAuthenticateTests.testJwkSetUpdates" -Dtests.seed=6B2F4ED558B90FA -Dtests.locale=bg -Dtests.timezone=Cuba -Druntime.java=17`

**Applicable branches:**
main

**Reproduces locally?:**
No

**Failure history:**
https://gradle-enterprise.elastic.co/scans/tests?tests.container=org.elasticsearch.xpack.security.authc.jwt.JwtRealmAuthenticateTests&tests.test=testJwkSetUpdates

**Failure excerpt:**
```
java.lang.AssertionError: 
Expected: is <false>
     but: was <true>

  at __randomizedtesting.SeedInfo.seed([6B2F4ED558B90FA:346D5564AC84C16E]:0)
  at org.hamcrest.MatcherAssert.assertThat(MatcherAssert.java:18)
  at org.junit.Assert.assertThat(Assert.java:956)
  at org.junit.Assert.assertThat(Assert.java:923)
  at org.elasticsearch.xpack.security.authc.jwt.JwtRealmTestCase.verifyAuthenticateFailureHelper(JwtRealmTestCase.java:121)
  at org.elasticsearch.xpack.security.authc.jwt.JwtRealmAuthenticateTests.testJwkSetUpdates(JwtRealmAuthenticateTests.java:227)
  at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(NativeMethodAccessorImpl.java:-2)
  at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
  at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
  at java.lang.reflect.Method.invoke(Method.java:568)
  at com.carrotsearch.randomizedtesting.RandomizedRunner.invoke(RandomizedRunner.java:1758)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$8.evaluate(RandomizedRunner.java:946)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$9.evaluate(RandomizedRunner.java:982)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$10.evaluate(RandomizedRunner.java:996)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.tests.util.TestRuleSetupTeardownChained$1.evaluate(TestRuleSetupTeardownChained.java:44)
  at org.apache.lucene.tests.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:43)
  at org.apache.lucene.tests.util.TestRuleThreadAndTestName$1.evaluate(TestRuleThreadAndTestName.java:45)
  at org.apache.lucene.tests.util.TestRuleIgnoreAfterMaxFailures$1.evaluate(TestRuleIgnoreAfterMaxFailures.java:60)
  at org.apache.lucene.tests.util.TestRuleMarkFailure$1.evaluate(TestRuleMarkFailure.java:44)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$StatementRunner.run(ThreadLeakControl.java:390)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl.forkTimeoutingTask(ThreadLeakControl.java:843)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$3.evaluate(ThreadLeakControl.java:490)
  at com.carrotsearch.randomizedtesting.RandomizedRunner.runSingleTest(RandomizedRunner.java:955)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$5.evaluate(RandomizedRunner.java:840)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$6.evaluate(RandomizedRunner.java:891)
  at com.carrotsearch.randomizedtesting.RandomizedRunner$7.evaluate(RandomizedRunner.java:902)
  at org.apache.lucene.tests.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:43)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.tests.util.TestRuleStoreClassName$1.evaluate(TestRuleStoreClassName.java:38)
  at com.carrotsearch.randomizedtesting.rules.NoShadowingOrOverridesOnMethodsRule$1.evaluate(NoShadowingOrOverridesOnMethodsRule.java:40)
  at com.carrotsearch.randomizedtesting.rules.NoShadowingOrOverridesOnMethodsRule$1.evaluate(NoShadowingOrOverridesOnMethodsRule.java:40)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at org.apache.lucene.tests.util.TestRuleAssertionsRequired$1.evaluate(TestRuleAssertionsRequired.java:53)
  at org.apache.lucene.tests.util.AbstractBeforeAfterRule$1.evaluate(AbstractBeforeAfterRule.java:43)
  at org.apache.lucene.tests.util.TestRuleMarkFailure$1.evaluate(TestRuleMarkFailure.java:44)
  at org.apache.lucene.tests.util.TestRuleIgnoreAfterMaxFailures$1.evaluate(TestRuleIgnoreAfterMaxFailures.java:60)
  at org.apache.lucene.tests.util.TestRuleIgnoreTestSuites$1.evaluate(TestRuleIgnoreTestSuites.java:47)
  at com.carrotsearch.randomizedtesting.rules.StatementAdapter.evaluate(StatementAdapter.java:36)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl$StatementRunner.run(ThreadLeakControl.java:390)
  at com.carrotsearch.randomizedtesting.ThreadLeakControl.lambda$forkTimeoutingTask$0(ThreadLeakControl.java:850)
  at java.lang.Thread.run(Thread.java:833)

```
x-pack/plugin/security/src/main/java/org/elasticsearch/xpack/security/authc/jwt/JwtSignatureValidator.java
reloadNotifier.reloaded();
                    if (jwkSetLoader.getContentAndJwksAlgs().jwksAlgs().isEmpty()) {
                        logger.debug("Reloaded empty PKC JWKs, signature verification will fail for JWT [{}]", tokenPrincipal);
                        
                    }
                    try {
                        JwtValidateUtil.validateSignature(signedJWT, jwkSetLoader.getContentAndJwksAlgs().jwksAlgs().jwks());
                        listener.onResponse(null);
                    } catch (Exception secondaryException) {
                        logger.debug(
                            "Signature verification of JWT [{}] failed - original failure: [{}], failure after reload: [{}]",
                            tokenPrincipal,
                            primaryException.getMessage(),
                            secondaryException.getMessage()
                        );
                        secondaryException.addSuppressed(primaryException);
                        listener.onFailure(secondaryException);
                    }
                }, listener::onFailure));
            }
        }
        @Override
        public void close() {
            jwkSetLoader.close();
        }
    }
    interface PkcJwkSetReloadNotifier {