Bump actions/checkout from 4 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v4...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/ci-cd.yml

@@ -40,7 +40,7 @@ jobs:
         shell: pwsh
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Cache NuGet packages
         uses: actions/cache@v4
@@ -94,7 +94,7 @@ jobs:
       cancel-in-progress: false
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Cache NuGet packages
         uses: actions/cache@v4
@@ -141,7 +141,7 @@ jobs:
         shell: pwsh
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Cache NuGet packages
         uses: actions/cache@v4

.github/workflows/sync-configurable-files.yml

@@ -37,7 +37,7 @@ jobs:
 
     steps:
       - name: Checkout current repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           token: ${{ secrets.SYNC_PAT || secrets.GITHUB_TOKEN }}
           fetch-depth: 0