Release is not idempotent

[joshmgross]

• Update release workflow to support re-publishing existing releases #1234
• Ensure script/release.sh is idempotent #1235

Even with #1235, re-releasing fails when attempting to upload artifacts to the GitHub Release:

  ⨯ release failed after 6m57s                       error=scm releases: failed to publish artifacts: failed to upload pscale_0.278.0_macOS_amd64.tar.gz: POST https://uploads.github.com/repos/planetscale/cli/releases/303388482/assets?name=pscale_0.278.0_macOS_amd64.tar.gz: 422 Validation Failed [{Resource:ReleaseAsset Field:name Code:already_exists Message:}]

https://github.com/planetscale/cli/actions/runs/23770631746/job/69261024826

I expected replace_existing_artifacts to resolve that, but it did not. There doesn't appear to be a way to skip the main publish step and run the other release steps, and GoReleaser's own docs say to only run once per tag

3. You are running GoReleaser multiple times against the same tag
   This one is easier to fix: make sure you are running GoReleaser only on tags, and only one time per tag.

https://goreleaser.com/resources/errors/release-upload/

For now, we'll need to release a new version if anything fails during a release.