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/changelog.yml

@@ -13,7 +13,7 @@ jobs:
 
         steps:
             -   name: Checkout code
-                uses: actions/checkout@v3
+                uses: actions/checkout@v4
 
             -   name: Setup PHP
                 uses: shivammathur/setup-php@v2

.github/workflows/code-style.yml

@@ -10,7 +10,7 @@ jobs:
 
         steps:
             -   name: Checkout code
-                uses: actions/checkout@v3
+                uses: actions/checkout@v4
 
             -   name: Detect job name
                 id: detect

.github/workflows/phpunit.yml

@@ -22,7 +22,7 @@ jobs:
 
         steps:
             -   name: Checkout code
-                uses: actions/checkout@v3
+                uses: actions/checkout@v4
 
             -   name: Setup PHP
                 uses: shivammathur/setup-php@v2