Bump actions/checkout from 5 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...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/badge.yml

@@ -18,7 +18,7 @@ jobs:
     steps:
       # Checkout Code (current branch)
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       # Use the output from the `coverage` step
       - name: Generate the badge SVG image

.github/workflows/ci.yml

@@ -25,7 +25,7 @@ jobs:
     steps:
       # Checkout Code (current branch)
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       # Install PHP
       - name: Setup PHP, with composer and extensions