utils/github: Use constant everywhere for "create a PAT" message
utils/github: Use constant everywhere for "create a PAT" message

- This way if we ever change this messaging, we only have to do so once.

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