Bump actions/checkout from 3 to 4

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3...v4)

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

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

.github/workflows/ci.yml

@@ -16,7 +16,7 @@ jobs:
         php-versions: [ '7.4' ]
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Setup PHP, with composer and extensions
         uses: shivammathur/setup-php@v2 #https://github.com/shivammathur/setup-php
@@ -78,7 +78,7 @@ jobs:
           - 5432:5432
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Setup PHP, with composer and extensions
         uses: shivammathur/setup-php@v2 #https://github.com/shivammathur/setup-php