Build(deps-dev): Bump minitest from 5.17.0 to 5.18.0 (#20538)

Bumps [minitest](https://github.com/seattlerb/minitest) from 5.17.0 to 5.18.0.
- [Release notes](https://github.com/seattlerb/minitest/releases)
- [Changelog](https://github.com/minitest/minitest/blob/master/History.rdoc)
- [Commits](https://github.com/seattlerb/minitest/compare/v5.17.0...v5.18.0)

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Gemfile.lock

@@ -240,7 +240,7 @@ GEM
     mini_sql (1.4.0)
     mini_suffix (0.3.3)
       ffi (~> 1.9)
-    minitest (5.17.0)
+    minitest (5.18.0)
     mocha (2.0.2)
       ruby2_keywords (>= 0.0.5)
     msgpack (1.6.1)