Bump minitest from 5.16.3 to 5.20.0

Bumps [minitest](https://github.com/minitest/minitest) from 5.16.3 to 5.20.0.
- [Changelog](https://github.com/minitest/minitest/blob/master/History.rdoc)
- [Commits](minitest/minitest@v5.16.3...v5.20.0)

---
updated-dependencies:
- dependency-name: minitest
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Gemfile.lock

@@ -30,7 +30,7 @@ GEM
     loofah (2.21.3)
       crass (~> 1.0.2)
       nokogiri (>= 1.12.0)
-    minitest (5.16.3)
+    minitest (5.20.0)
     nokogiri (1.15.4-arm64-darwin)
       racc (~> 1.4)
     nokogiri (1.15.4-x86_64-darwin)