Mute RotatableSecretTests#testBasicRotation (#99761)

See https://github.com/elastic/elasticsearch/issues/99759

server/src/test/java/org/elasticsearch/common/settings/RotatableSecretTests.java

@@ -27,6 +27,7 @@ public class RotatableSecretTests extends ESTestCase {
     private final SecureString secret2 = new SecureString(randomAlphaOfLength(10));
     private final SecureString secret3 = new SecureString(randomAlphaOfLength(10));
 
+    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/99759")
     public void testBasicRotation() throws Exception {
         // initial state
         RotatableSecret rotatableSecret = new RotatableSecret(secret1);