Bump actions/checkout from 3 to 4 (#29)

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]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/php-ci.yml

@@ -12,7 +12,7 @@ jobs:
 
     name: PHP (Latest) - Build and Archive
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Validate composer.json and composer.lock
         uses: php-actions/composer@v6
@@ -58,7 +58,7 @@ jobs:
         run: tar -xvf /tmp/builds/build.tar ./
 
       - name: Checkout FOSSBilling Source Code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           repository: "FOSSBilling/FOSSBilling"
           path: "FOSSBilling"
@@ -98,7 +98,7 @@ jobs:
         id: get_id
 
       - name: Checkout The Release tag
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           repository: "FOSSBilling/FOSSBilling"
           path: "FOSSBilling"

.github/workflows/preview.yml

@@ -18,7 +18,7 @@ jobs:
     name: Create a downloadable preview build
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Install PHP
         uses: shivammathur/setup-php@v2

.github/workflows/spellcheck.yml

@@ -11,7 +11,7 @@ jobs:
   spellcheck:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: streetsidesoftware/cspell-action@v3
         with:
           incremental_files_only: true