Bump actions/checkout from 4 to 6

.github/workflows/ci.yml

@@ -25,14 +25,14 @@ jobs:
         php-version: ['7.2']
     steps:
       - name: Checkout phpBB
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           repository: phpbb/phpbb
           ref: ${{ env.PHPBB_BRANCH }}
           path: phpBB3
 
       - name: Checkout extension
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           path: extension
 
@@ -153,14 +153,14 @@ jobs:
             db-version: '10.6'
     steps:
       - name: Checkout phpBB
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           repository: phpbb/phpbb
           ref: ${{ env.PHPBB_BRANCH }}
           path: phpBB3
 
       - name: Checkout extension
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           path: extension
 
@@ -253,14 +253,14 @@ jobs:
             db-version: '16-alpine'
     steps:
       - name: Checkout phpBB
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           repository: phpbb/phpbb
           ref: ${{ env.PHPBB_BRANCH }}
           path: phpBB3
 
       - name: Checkout extension
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           path: extension
 
@@ -325,7 +325,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout extension
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           path: extension