Bump actions/checkout from 6 to 7

Bumps [actions/checkout](https://github.com/actions/checkout) from 6 to 7.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v6...v7)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/cd.yml

@@ -27,7 +27,7 @@ jobs:
       id-token: write     # Required for NuGet Trusted Publishing; without it NuGet/login fails with 403.
       contents: write     # Required to create the GitHub Release; a job-level block drops inherited defaults.
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
 
       - name: Setup .NET
         uses: actions/setup-dotnet@v5

.github/workflows/ci.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: windows-latest
     timeout-minutes: 15
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v7
 
       - name: Setup .NET
         uses: actions/setup-dotnet@v5