Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/branch-validations.yaml

@@ -15,7 +15,7 @@ jobs:
   security-checks:
    runs-on: ubuntu-latest
    steps:
-     - uses: actions/checkout@v5
+     - uses: actions/checkout@v6
      - uses: actions/setup-node@v6
        with:
          registry-url: 'https://registry.npmjs.org'
@@ -40,7 +40,7 @@ jobs:
   validate:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-node@v6
         with:
           node-version: 23
@@ -64,7 +64,7 @@ jobs:
     needs:
       - validate
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-node@v6
         with:
           node-version: 23
@@ -88,7 +88,7 @@ jobs:
     needs:
       - validate
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-node@v6
         with:
           node-version: 23

.github/workflows/deploy-published-releases.yaml

@@ -9,7 +9,7 @@ jobs:
   deploy:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-node@v6
         with:
           registry-url: 'https://registry.npmjs.org'

.github/workflows/publish-pr-preview.yaml

@@ -10,7 +10,7 @@ jobs:
   preview:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-node@v6
         with:
           node-version: 23