gh-actions(deps): update actions/checkout requirement to v2.3.4

Updates the requirements on [actions/checkout](https://github.com/actions/checkout) to permit the latest version.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/commits/5a4ac9002d0be2fb38bd78e4b4dbde5606d7042f)

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

Author: dependabot[bot]

.github/workflows/php.yml

@@ -15,7 +15,7 @@ jobs:
     name: PHP ${{ matrix.os}} ${{ matrix.php-versions }}
     steps:
       - name: Checkout
-        uses: actions/checkout@v1
+        uses: actions/checkout@v2.3.4
       - name: Setup PHP
         uses: shivammathur/setup-php@master
         with:

.github/workflows/release.yml

@@ -28,7 +28,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 30
     steps:
-      - uses: actions/[email protected].3
+      - uses: actions/[email protected].4
 
       - name: Set the version
         id: set_version