Re-enable `vendor-gems` for pull requests.
Re-enable `vendor-gems` for pull requests.

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