Bump actions/checkout from 5 to 6 in the all group (#29)

Bumps the all group with 1 update: [actions/checkout](https://github.com/actions/checkout).


Updates `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
  dependency-group: all
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/dotnet-format.yml

@@ -13,7 +13,7 @@ jobs:
   build:
     runs-on: windows-latest
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
 
     - name: Setup .NET
       uses: actions/setup-dotnet@v5

.github/workflows/dotnet-test.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: windows-latest
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
 
     - name: Setup .NET
       uses: actions/setup-dotnet@v5