Change release to use personal github token

[TonyGiorgio]

Feel free to ignore if you don't want to change it, but it would appear that github behaves differently on forks of projects where GITHUB_TOKEN is used, I guess out of caution.

This changes to PERSONAL_TOKEN which does require you to generate a classic token manually in the settings with repo permissions. All forks that want to still use release CI would have to do this (unless there is some other github workaround I'm not aware of).