Bump actions/setup-dotnet from 4 to 6

Bumps [actions/setup-dotnet](https://github.com/actions/setup-dotnet) from 4 to 6.
- [Release notes](https://github.com/actions/setup-dotnet/releases)
- [Commits](actions/setup-dotnet@v4...v6)

---
updated-dependencies:
- dependency-name: actions/setup-dotnet
  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/build.yml

@@ -10,7 +10,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: actions/setup-dotnet@v4
+      - uses: actions/setup-dotnet@v6
         with:
           dotnet-version: '9.0.x'