Bump actions/checkout from 2 to 3 (#88)

Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 3.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v2...v3)

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

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

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

Author: dependabot[bot]

.github/workflows/gem-push.yml

@@ -11,7 +11,7 @@ jobs:
       packages: write
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - name: Set up Ruby 2.6
       uses: actions/setup-ruby@v1
       with:

.github/workflows/ruby.yml

@@ -15,7 +15,7 @@ jobs:
         ruby-version: ['2.5', '2.7', '3.0', '3.1', '3.2']
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - name: Set up Ruby
       uses: ruby/setup-ruby@v1
       with: