Bump actions/checkout from 3 to 4 (#132)

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

.github/workflows/nox.yml

@@ -26,7 +26,7 @@ jobs:
         working-directory: antsibull-changelog
     steps:
       - name: Check out antsibull-changelog
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           path: antsibull-changelog
       - name: Setup nox
@@ -42,7 +42,7 @@ jobs:
         working-directory: antsibull-changelog
     steps:
       - name: Check out antsibull-changelog
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           path: antsibull-changelog
       - name: Setup nox
@@ -66,7 +66,7 @@ jobs:
         working-directory: antsibull-changelog
     steps:
       - name: Check out antsibull-changelog
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           path: antsibull-changelog
       - name: Setup nox