Bump actions/checkout from 4 to 5 (php#4855)

Author: dependabot[bot]

.github/workflows/check-whitespace.yml

@@ -16,7 +16,7 @@ jobs:
   check-whitespace:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 0
 

.github/workflows/integrate.yaml

@@ -24,20 +24,20 @@ jobs:
 
     steps:
       - name: "Checkout php/doc-${{ matrix.language }}"
-        uses: "actions/checkout@v4"
+        uses: "actions/checkout@v5"
         with:
           path: "${{ matrix.language }}"
           repository: "php/doc-${{ matrix.language }}"
 
       - name: "Checkout php/doc-en as fallback"
         if: "matrix.language != 'en'"
-        uses: "actions/checkout@v4"
+        uses: "actions/checkout@v5"
         with:
           path: "en"
           repository: "php/doc-en"
 
       - name: "Checkout php/doc-base"
-        uses: "actions/checkout@v4"
+        uses: "actions/checkout@v5"
         with:
           path: "doc-base"
           repository: "php/doc-base"