build(deps-dev): bump shoulda-matchers from 6.3.1 to 6.4.0

Bumps [shoulda-matchers](https://github.com/thoughtbot/shoulda-matchers) from 6.3.1 to 6.4.0.
- [Release notes](https://github.com/thoughtbot/shoulda-matchers/releases)
- [Changelog](https://github.com/thoughtbot/shoulda-matchers/blob/main/CHANGELOG.md)
- [Commits](thoughtbot/shoulda-matchers@v6.3.1...v6.4.0)

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

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

Gemfile.lock

@@ -734,7 +734,7 @@ GEM
     mini_magick (5.0.1)
     mini_mime (1.1.5)
     mini_portile2 (2.8.7)
-    minitest (5.25.0)
+    minitest (5.25.1)
     msgpack (1.7.2)
     multi_json (1.15.0)
     mustermann (3.0.2)
@@ -1046,7 +1046,7 @@ GEM
       websocket (~> 1.0)
     semantic (1.6.1)
     shoulda-context (2.0.0)
-    shoulda-matchers (6.3.1)
+    shoulda-matchers (6.4.0)
       activesupport (>= 5.2.0)
     signet (0.19.0)
       addressable (~> 2.8)