Fix retain cycles in AnnouncementsDataStoreTests and GutenbergVideoUploadProcessor

[amanjeetsingh150]

Closes #25547.

Report:

wp-local-audit-Xcode26.0.zip

Description

Fixes two distinct retain cycles surfaced by XCTestLeaks against the WordPress scheme.

1. AnnouncementsDataStoreTests (test code)

store → changeDispatcher → observers[token] → closure → store

The four tests stash subscription = store.onChange { … store.x … } as an instance property; the closure captures the local store strongly and is retained by Dispatcher.observers. Without a tearDown the Receipt only deinits when XCTest tears the test instance down, which is deferred when the class has multiple queued tests — long enough for the post-test leak snapshot to observe the cycle.

Fix: add tearDown that nils subscription. The Receipt's deinit then calls unsubscribe immediately, removing the closure from observers and breaking the cycle.

2. GutenbergVideoUploadProcessor (production code)

GutenbergVideoUploadProcessor
  → videoHtmlProcessor (HTMLProcessor) [lazy strong]
    → replacer.context → captures self strongly
      → GutenbergVideoUploadProcessor (cycle)

Three lazy var properties construct child processors whose replacer: closures reference self.remoteURLString / self.mediaUploadID without a capture list. Each lazy property is strongly owned by self and retains a closure that captures self strongly — three independent two-node cycles.

Fix: [weak self] + guard let self in all three closures. By ownership the closure can only execute while self is alive, so the guard is never tripped in practice.

Testing

# Cycle 1
xctestleaks agent run \\
  --workspace WordPress.xcworkspace --scheme WordPress \\
  --only-testing "WordPressTest/AnnouncementsDataStoreTests"

# Cycle 2
xctestleaks agent run \\
  --workspace WordPress.xcworkspace --scheme WordPress \\
  --only-testing "WordPressTest/GutenbergVideoUploadProcessorTests/testMediaTextBlockProcessor"

Both reported 0 leaks on this branch and the original leak counts on trunk.

Notes for reviewers

The first leak is in test file, I'm open to revert let me know how'd you feel about it. The second one is production leak and we can get that in.