69041 Update null safe deps to prepare for the 2.12 sdk version (cla: yes, team, tool, waiting for tree to go green)

69043 [null-safety] add language version to freeform template (cla: yes, team)

69046 Print errors in all build modes (cla: yes, framework, team, waiting for tree to go green)

69047 [flutter_tools] do not include AS validator if android is not enabled (cla: yes)

69048 Migrate Flutter gallery test to null safety (cla: yes, f: cupertino, f: material design, team)

69050 InheritedTheme updates (cla: yes, f: material design, framework, waiting for tree to go green)

69055 Make WidgetsLocalizations.of non-nullable (cla: yes, framework)