Bump bref/bref from 2.1.17 to 2.1.20

Bumps [bref/bref](https://github.com/brefphp/bref) from 2.1.17 to 2.1.20.
- [Release notes](https://github.com/brefphp/bref/releases)
- [Commits](brefphp/bref@2.1.17...2.1.20)

---
updated-dependencies:
- dependency-name: bref/bref
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>