workflows/tests: run brew style on taps.
workflows/tests: run brew style on taps.

Also, clarify where `brew readall` is run.

nandub/brew,MikeMcQuaid/brew,EricFromCanada/brew,konqui/brew,claui/brew,Homebrew/brew,claui/brew,vitorgalvao/brew,konqui/brew,JCount/brew,konqui/brew,sjackman/homebrew,JCount/brew,JCount/brew,Homebrew/brew,MikeMcQuaid/brew,vitorgalvao/brew,sjackman/homebrew,nandub/brew,EricFromCanada/brew,reitermarkus/brew,claui/brew,Homebrew/brew,mahori/brew,reitermarkus/brew,Homebrew/brew,reitermarkus/brew,reitermarkus/brew,sjackman/homebrew,mahori/brew,sjackman/homebrew,mahori/brew,konqui/brew,vitorgalvao/brew,nandub/brew,MikeMcQuaid/brew,mahori/brew,EricFromCanada/brew,JCount/brew,claui/brew,MikeMcQuaid/brew,vitorgalvao/brew,nandub/brew,EricFromCanada/brew