Run `brew typecheck homebrew/aliases` in CI

[issyl0]

• I realised this repo doesn't run brew test-bot --only-tap-syntax, but making it do that seemed like too much overhead, so let's just run brew tc along with brew style and the actual command, brew alias.
• I felt like we should probably test adding an alias, too.

[MikeMcQuaid]

• I realised this repo doesn't run brew test-bot --only-tap-syntax, but making it do that seemed like too much overhead

Would rather this ran brew test-bot --only-tap-syntax instead!

[MikeMcQuaid]

Thanks @issyl0!