Bump actions/checkout from 5 to 6 (#34)

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...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] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Setup .NET SDK
         uses: actions/setup-dotnet@v5
         with:
@@ -49,7 +49,7 @@ jobs:
       version: ${{ steps.get-version.outputs.version }}
     steps:
     - name: Checkout
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
     - name: Setup .NET SDK
       uses: actions/setup-dotnet@v5
       with:
@@ -102,7 +102,7 @@ jobs:
     needs: build-nuget
     steps:
     - name: Checkout
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
     - name: Download NuGet artifact
       uses: actions/download-artifact@v6
       with:
@@ -152,7 +152,7 @@ jobs:
     needs: [build-nuget, all-required-checks-done]
     steps:
     - name: Checkout
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
     - name: Check version
       id: check-version
       shell: pwsh