openslide-bin release process

~If there's a new OpenSlide release, remove dev_deps condition from any subprojects used by the new release~
[x] Run workflow to check for updates
[x] Merge any resulting PR; perform any needed manual updates reported by the workflow
[x] Submit PR to update CHANGELOG.md and _PROJECT_VERSION
[x] Land PR
[x] Create and push signed tag
[x] Find the workflow run for the tag
- [x] Once the build finishes, approve deployment to PyPI
[x] Verify that CI creates a PyPI release with a description, source tarball, and wheels
[x] Verify that CI creates a GitHub release with release notes, software versions, and artifacts
[x] Update website: _data/releases.yaml, maybe _includes/news.md
[x] Possibly send mail to ~-announce and~ -users
~Possibly post to forum.image.sc~

openslide / openslide-bin