Bump actions/checkout from 3 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3...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] <[email protected]>

Author: dependabot[bot]

.github/workflows/composer-normalize.yml

@@ -10,7 +10,7 @@ jobs:
         runs-on: ubuntu-latest
         steps:
             - name: Git checkout
-              uses: actions/checkout@v3
+              uses: actions/checkout@v6
 
             - name: normalize composer.json
               run: |

.github/workflows/php-cs-fixer.yml

@@ -8,7 +8,7 @@ jobs:
 
         steps:
             - name: Checkout code
-              uses: actions/checkout@v3
+              uses: actions/checkout@v6
               with:
                   ref: ${{ github.head_ref }}
 

.github/workflows/run-tests.yml

@@ -25,7 +25,7 @@ jobs:
 
         steps:
             - name: Checkout code
-              uses: actions/checkout@v4
+              uses: actions/checkout@v6
 
             - name: Setup PHP
               uses: shivammathur/setup-php@v2

.github/workflows/update-changelog.yml

@@ -10,7 +10,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v6
         with:
           ref: main