Bump kamal from 2.1.1 to 2.2.1

Bumps [kamal](https://github.com/basecamp/kamal) from 2.1.1 to 2.2.1.
- [Release notes](https://github.com/basecamp/kamal/releases)
- [Commits](basecamp/kamal@v2.1.1...v2.2.1)

---
updated-dependencies:
- dependency-name: kamal
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Gemfile.lock

@@ -128,7 +128,7 @@ GEM
       actionview (>= 5.0.0)
       activesupport (>= 5.0.0)
     json (2.7.2)
-    kamal (2.1.1)
+    kamal (2.2.1)
       activesupport (>= 7.0)
       base64 (~> 0.2)
       bcrypt_pbkdf (~> 1.0)