Branch not folding back in after squash and delete upstream PR merge

[gitbutler-client]

I have one more fun bug: If I have a virtual branch and the upstream pr gets merged (we use squash and delete), but I had already accumulated merge commits that I didn't push up (because why would I?), and now the branch doesn't get folded back in, even though its merged (note: this is when "allow force pushing" is disabled)

https://discord.com/channels/1060193121130000425/1060193121666863156/1208092681713094716