Use a GitHub app for sync-team

[marcoieni]

Right now to apply the changes, we use a classic PAT.
We want to create a GitHub app with write permissions and install it on all orgs.

Question to be confirmed:

• is it possible to install a GitHub app with write permissions for all repositories?
• can we use merge-bots with a GitHub app? The read only github app can't read actors that are allowed to push. e.g.: