ci: bump actions/checkout from 2 to 4

Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v2...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>

.github/workflows/ci.yml

@@ -11,7 +11,7 @@ jobs:
       image: fedora:latest
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
 
     - name: Install RPM build deps
       run: |

.github/workflows/translations.yml

@@ -24,7 +24,7 @@ jobs:
       run: |
         dnf install -y python3-setuptools gettext git diffutils
 
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
       with:
         # This fetches full git history. We need that for proper
         # branch updating