81686 Add “onTap” callback to PopupMenuItem (framework, f: material design, cla: yes)

81699 Fixed some trivial formatting issues in test/material/popup_menu_test.dart (framework, f: material design, cla: yes)

81706 Integrate MaterialBanner with the ScaffoldMessenger API (severe: new feature, framework, a: animation, f: material design, a: fidelity, cla: yes, d: api docs, d: examples, a: quality, waiting for tree to go green, documentation)

81792 Reduce potential collisions from Gold RNG (a: tests, team, framework, cla: yes, team: flakes, waiting for tree to go green, team: infra, team: presubmit flakes)

81794 Reland GC related bench update (a: tests, team, framework, cla: yes, waiting for tree to go green)