Adding Support for `pull_request.reopened`

[louisunlimited]

The current behavior does not allow this action to be ran when a pr has been closed & reopened.

✖  error     Event `pull_request.reopened` is not supported by this action.

I first encounter this because the action is not picking up branch names correctly and I was trying to force a fresh run by closing & reopening this pr.

Is this intentional or can be provide support for reopened pull requests?