27882 [web] remove implicit casts and implicit dynamic (cla: yes, platform-web)

27911 [web] Fix types of some event listeners (cla: yes, platform-web, needs tests)

27932 Fix routerinformationupdate can take complex json (cla: yes, platform-web)

27972 Fix: modifier keys not recognized on macOS Web (cla: yes, platform-web, cp: 2.5)

27977 [canvaskit] Release overlays to the cache once they have been used (cla: yes, platform-web)

27985 [web_ui] Fixed aria-live attribute on web (cla: yes, platform-web)

27995 [web] rename watcher.dart to pipeline.dart (cla: yes, waiting for tree to go green, platform-web, needs tests)