Bump actions/checkout from 3 to 4 (#96)

* Bump actions/checkout from 3 to 4

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3...v4)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

* Cleanup rubies/rails.

---------

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -9,15 +9,13 @@ jobs:
     strategy:
       matrix:
         ruby: [2.7, '3.0', '3.1', 3.2]
-        rails: [6, 7]
+        rails: [6, '7.0', '7.1']
         exclude:
-          - ruby: '2.7'
-            rails: 7
           - ruby: 3.2
             rails: 6
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
 
     - uses: ruby/setup-ruby@v1
       with: