* 6.x:
  Unmute IndexUpgradeIT tests
  Forbid expensive query parts in ranking evaluation (#30151)
  Docs: Update HighLevelRestClient migration docs (#30544)
  Clients: Switch to new performRequest (#30543)
  [TEST] Fix typo in MovAvgIT test
  [TEST] Mute ML test that needs updating to following ml-cpp changes
  Moved tokenizers to analysis common module (#30538)
  Document woes between auto-expand-replicas and allocation filtering (#30531)
  [ML] Hide internal Job update options from the REST API (#30537)
  Deprecate not copy settings and explicitly disallow (#30404)
  Mute ShrinkIndexIT suite
  SQL: SYS TABLES ordered according to *DBC specs (#30530)
  [ML] Improve state persistence log message
  Build: Add mavenPlugin cluster configuration method (#30541)
  Re-enable FlushIT tests
  Bump Gradle heap to 2 GB (#30535)
  Bump Gradle heap to 1792m (#30484)
  SQL: Use request flavored methods in tests (#30345)
  Suppress hdfsFixture if there are spaces in the path (#30302)
  Delete temporary blobs before creating index file (#30528)
  Watcher: Remove TriggerEngine.getJobCount() (#30395)
  Use simpler write-once semantics for FS repository (#30435)
  Use simpler write-once semantics for HDFS repository (#30439)
  SQL: Improve correctness of SYS COLUMNS & TYPES (#30418)
  Mute two tests in FlushIT with @AwaitsFix.
  Fix incorrect template name in test case
  Build: Remove legacy bwc files from xpack (#30485)
  Security: Simplify security index listeners (#30466)
  Mute SharedClusterSnapshotRestoreIT#testSnapshotSucceedsAfterSnapshotFailure with @AwaitsFix.
  Add proper longitude validation in geo_polygon_query (#30497)
  Mute UnicastZenPingTests#testSimplePings with @AwaitsFix.
  Security: cleanup code in file stores (#30348)
  Security: fix TokenMetaData equals and hashcode (#30347)
  Mute two tests from SmokeTestWatcherWithSecurityClientYamlTestSuiteIT.
  Fix incorrect merged entry in changelog
  SQL: Improve compatibility with MS query (#30516)
  SQL: Fix parsing of dates with milliseconds (#30419)