63649 gen_l10n: support string list as preferred-supported-locales, as documented (cla: yes, team, tool)

63697 [flutter_tools] remove most globals from build system and tests (cla: yes, tool, waiting for tree to go green)

63707 Surface Windows build errors in non-verbose mode (a: build, a: desktop, cla: yes, platform-windows, tool, waiting for tree to go green)

63795 Return host and port from devtools launcher (cla: yes, tool, waiting for tree to go green)

63796 [flutter_tool] Fix some create_test.dart tests on Windows (cla: yes, tool)

63806 [flutter_tool] Handle Windows line endings in packages_test.dart (cla: yes, tool, waiting for tree to go green)