Add flag to skip running hooks

Hi beautiful people, Scott [suggested](https://discord.com/channels/841451783728529451/1362169905083846838/1363885101825659054) i create an issue here.

I added some hooks to my `gel.toml` so that when i apply a migration it my codegen script runs (TS types, .edgeql builder, etc.).

Thing is they're being invoked in my CI when setting up the db with [`geldata/setup-gel`](https://github.com/geldata/setup-gel). I'd like to skip that (more so because it silently errors out).

As a start a flag to skip running the hooks would be needed, no? e.g. a global flag `--skip-hooks`. And then maybe i'll have to bother you at that other repo.

Thank you!