Bump vimeo/psalm from 5.18.0 to 5.20.0

Bumps [vimeo/psalm](https://github.com/vimeo/psalm) from 5.18.0 to 5.20.0.
- [Release notes](https://github.com/vimeo/psalm/releases)
- [Commits](vimeo/psalm@5.18.0...5.20.0)

---
updated-dependencies:
- dependency-name: vimeo/psalm
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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