78584 Revert “Fix a legacy TODO” (a: tests, cla: yes, framework, team)

78588 Automatically applying Scrollbars on desktop platforms with configurable ScrollBehaviors (a: desktop, cla: yes, customer: crowd, f: cupertino, f: material design, framework, platform-web, severe: API break, severe: new feature, waiting for tree to go green)

78592 Skip linking against Flutter for CocoaPods transitive dependencies (cla: yes, platform-ios, t: xcode, team, tool, waiting for tree to go green)

78619 Enable null safety by default in templates (cla: yes, tool)

78623 Reverts “Implement dartPluginClass support for plugins #74469” (cla: yes, d: examples, team, tool)