Snapshot release fails if repository is in pre-release mode

[alvrs]

It seems like it is not possible to create snapshot releases if the repository is in the prerelease mode.

🦋  warn ===============================IMPORTANT!===============================
🦋  error Snapshot release is not allowed in pre mode
🦋  To resolve this exit the pre mode by running `changeset pre exit`

(see https://github.com/latticexyz/mud/actions/runs/5683670374/job/15404709041#step:7:17)

What is the reason this is not allowed?

[alessbell]

Fwiw @alvrs I've worked around this by detecting and removing pre.json to allow snapshot releases from PRs made against a long-running prerelease branch. Also not sure why the restriction exists but we've been using this workaround very happily now for many months and almost forgot it was there (edit: I see you're already doing that 🙂)