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](actions/checkout@v2...v4)

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

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

.github/workflows/php-linter.yml

@@ -17,7 +17,7 @@ jobs:
             php-version: ['7.4', '8.3']
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
         with:
           repository: ${{ github.event.client_payload.pull_request.head.repo.full_name }}
           ref: ${{ github.event.client_payload.pull_request.head.ref }}

.github/workflows/phpstan.yml

@@ -18,7 +18,7 @@ jobs:
       fail-fast: false
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
 
       - name: Setup PHP
         id: setup-php

.github/workflows/publish-to-redaxo-org.yml

@@ -10,7 +10,7 @@ jobs:
   redaxo_publish:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - uses: FriendsOfREDAXO/installer-action@v1
       with:
         myredaxo-username: ${{ secrets.MYREDAXO_USERNAME }}