build(deps): bump prosemirror-schema-list from 1.2.0 to 1.2.1

Bumps [prosemirror-schema-list](https://github.com/prosemirror/prosemirror-schema-list) from 1.2.0 to 1.2.1.
- [Release notes](https://github.com/prosemirror/prosemirror-schema-list/releases)
- [Changelog](https://github.com/ProseMirror/prosemirror-schema-list/blob/master/CHANGELOG.md)
- [Commits](ProseMirror/prosemirror-schema-list@1.2.0...1.2.1)

---
updated-dependencies:
- dependency-name: prosemirror-schema-list
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>