42863 V1.9.1 hotfixes (cla: yes, engine, team, tool)

42867 Use Cirrus credits for billing. (cla: yes, team, team: infra)

42872 Remove use_modular_headers from Podfiles using libraries (cla: yes, d: examples, team, team: gallery, tool)

42873 Update README to include non-mobile targets (cla: yes, team)

42879 Re-implement hardware keyboard text selection. (cla: yes, framework)

42882 Reenable the dartdocs benchmark tracking (cla: yes, team)

42922 Fix typo (cla: no, f: material design, framework)

42924 CupertinoDialogAction is missing super call (cla: yes, f: cupertino, framework, waiting for tree to go green)