89603 Update dartdoc to 3.0.0 (team, cla: yes, waiting for tree to go green)

89606 Directly specify keystore to prevent debug key signing flake in Deferred components integration test. (team, cla: yes, team: flakes, waiting for tree to go green, severe: flake)

89618 Run flutter_gallery ios tests on arm64 device (team, platform-ios, cla: yes, waiting for tree to go green)

89620 Run flutter_gallery macOS native tests on presubmit (a: tests, team, platform-mac, cla: yes, waiting for tree to go green, a: desktop)

89668 changed subprocesses to async from sync (team, cla: yes, waiting for tree to go green)