Prepare the spellabet v0.3.1 patch release

[senile-errata]

This PR was automatically created by the bump-version workflow, which ran the following commands:

$ cargo update --package spellabet
$ cargo release version --execute --package spellabet patch
$ cargo release replace --execute --package spellabet
$ prettier --prose-wrap always --write -- **/CHANGELOG.md

Please review the submitted changes.

Once this PR is merged into the main branch, an automated process will tag the commit and create a draft GitHub Release with assets attached for final review before publishing.