Update actions/checkout action to v5

| datasource  | package          | from | to |
| ----------- | ---------------- | ---- | -- |
| github-tags | actions/checkout | v4   | v5 |


Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/build_test.yml

@@ -32,7 +32,7 @@ jobs:
       - name: Show PHP version
         run: php -v
 
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         name: Checkout branch
 
       - name: Validate composer.json and composer.lock

.github/workflows/deploy-gh-pages.yml

@@ -23,7 +23,7 @@ jobs:
         shell: bash
         working-directory: ./docs
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: actions/setup-node@v4
         with:
           node-version: 18

.github/workflows/test-deploy-gh-pages.yml

@@ -17,7 +17,7 @@ jobs:
     name: Build GitHub Pages
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: actions/setup-node@v4
         with:
           node-version: 18