74657 Remove vestigial nullOk parameter from Localizations.localeOf (a: internationalization, cla: yes, framework)

74661 remove some stray nullOK mentions from docs (cla: yes, f: cupertino, f: material design, framework, waiting for tree to go green)

74663 Roll Plugins from 712dcc184380 to 18124285feeb (1 revision) (cla: yes, waiting for tree to go green)

74664 [flutter_tools] handle waitForExtension having no isolates (cla: yes, tool, waiting for tree to go green)

74665 Handle ‘Existing VM service clients’ error from old VM service instances (cla: yes, tool, waiting for tree to go green)