You could use the Cloud build github app in order to set the triggers as mentioned on this document. They do support both builds triggered with branches or tags, however you would not be able to trigger them with both.
You would need to create a separate trigger for the branch and for the tag, and also keep in mind that this feature is in beta, so I wouldn’t recommend you using this in any production environment.
Hope you find this useful.
solved Cloud-build Trigger [closed]