Fix the automated release process

[galargh]

The issues discovered during the v19.0.0 release:

• The default GitHub token used by release.yml cannot push d3d71d3 to the default branch because the default branch requires changes to be made through pull requests
• It cannot create a tag either because git push is performed atomically by cargo release
• The release commit created by cargo release does not contain changelog changes (e.g. 0e64ce8)