91267 Migrate protocol_discovery to null safety (tool, cla: yes, waiting for tree to go green, a: null-safety)

91268 Mark Linux deferred components to be flaky (cla: yes, waiting for tree to go green)

91271 Mark Linux_android flutter_gallery__start_up to be flaky (cla: yes, waiting for tree to go green)

91273 Marks Mac_ios integration_ui_ios_textfield to be flaky (cla: yes, waiting for tree to go green)

91281 Don’t generate plugin registry in ResidentWebRunner (tool, cla: yes, waiting for tree to go green)

91300 Remove 10 second timewarp in integration test pubspec.yamls (tool, cla: yes)

91301 Suppress diagnostics from // HACK comments (cla: yes)