Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/ci.yml

@@ -230,7 +230,7 @@ jobs:
     if: github.event_name == 'pull_request'
     steps:
       - name: Checkout PR head commit
-        uses: actions/checkout@v4
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
         with:
           ref: ${{ github.event.pull_request.head.sha }}
           fetch-depth: 0
@@ -826,7 +826,7 @@ jobs:
       packages: write
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
         with:
           submodules: true
 
@@ -1086,7 +1086,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
 
       - uses: actions/setup-node@53b83947a5a98c8d113130e565377fae1a50d02f # v6
         env:
@@ -1129,7 +1129,7 @@ jobs:
       packages: write
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
 
       - name: Download public app artifacts
         uses: actions/download-artifact@v4

.github/workflows/copilot-setup-steps.yml

@@ -19,7 +19,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
       - name: Install gh-aw extension
         uses: github/gh-aw/actions/setup-cli@245d16844b16f61042aebf5931af62a750b202fc # v0.67.0
         with: