93094 Update minimum required version to Xcode 12.3 (a: text input, tool, cla: yes, waiting for tree to go green, t: xcode)

93128 Remove comment on caching line metrics (a: text input, framework, cla: yes, waiting for tree to go green)

93129 Use baseline value to get position in next line (a: text input, framework, cla: yes, waiting for tree to go green)

93166 Do not rebuild when TickerMode changes (a: text input, framework, cla: yes, waiting for tree to go green)

93168 [flutter_tools] Catch lack of flutter tools source missing (a: text input, tool, cla: yes)

93170 Desktop edge scrolling (a: text input, framework, f: material design, cla: yes, f: cupertino, waiting for tree to go green)