Bump appsignal from 4.2.1 to 4.2.3

Bumps [appsignal](https://github.com/appsignal/appsignal-ruby) from 4.2.1 to 4.2.3.
- [Changelog](https://github.com/appsignal/appsignal-ruby/blob/main/CHANGELOG.md)
- [Commits](appsignal/appsignal-ruby@v4.2.1...v4.2.3)

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

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

Gemfile.lock

@@ -114,7 +114,7 @@ GEM
     after_commit_everywhere (1.5.0)
       activerecord (>= 4.2)
       activesupport
-    appsignal (4.2.1)
+    appsignal (4.2.3)
       logger
       rack
     ast (2.4.2)