Bump actions/checkout from 4 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v4...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/build-and-push-docker-image.yml

@@ -42,7 +42,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Fetch built PHAR from artifacts
         uses: actions/download-artifact@v6

.github/workflows/build-phar.yml

@@ -37,7 +37,7 @@ jobs:
           coverage: none
           tools: composer, box
           php-version: "${{ matrix.php-version }}"
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
       # Fixes `git describe` picking the wrong tag - see https://github.com/php/pie/issues/307

.github/workflows/continuous-integration.yml

@@ -29,7 +29,7 @@ jobs:
           extensions: intl, sodium, zip
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: ramsey/composer-install@v3
       - name: GH token (non-Windows)
         if: matrix.operating-system != 'windows-latest'
@@ -118,7 +118,7 @@ jobs:
           make -j$(nproc)
           sudo make install
           cd $GITHUB_WORKSPACE
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Composer Install
         run: composer install --ignore-platform-reqs
       - name: Run bundled PHP install test
@@ -138,7 +138,7 @@ jobs:
           - '8.3'
           - '8.4'
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0
       # Fixes `git describe` picking the wrong tag - see https://github.com/php/pie/issues/307
@@ -165,7 +165,7 @@ jobs:
           extensions: intl, sodium, zip
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: ramsey/composer-install@v3
       - name: Run PHPCS
         run: vendor/bin/phpcs
@@ -180,7 +180,7 @@ jobs:
           extensions: intl, sodium, zip
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: ramsey/composer-install@v3
       - name: Validate the composer configuration
         run: composer validate --strict

.github/workflows/docs.yml

@@ -32,7 +32,7 @@ jobs:
       - build-phar
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Build documentation
         run: .github/docs/build-docs.sh
       - name: Fetch built PHAR from artifacts

.github/workflows/release.yml

@@ -25,7 +25,7 @@ jobs:
       # contents:write is required to create the draft release
       contents: write
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
         with:
           fetch-tags: 'true'
           ref: ${{ github.ref }}
@@ -47,7 +47,7 @@ jobs:
       # contents:write is required to upload the binaries to the release.
       contents: write
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Fetch built PHAR from artifacts
         uses: actions/download-artifact@v6
         with: