Bump actions/setup-dotnet from 4 to 5 (#1658)

Bumps [actions/setup-dotnet](https://github.com/actions/setup-dotnet) from 4 to 5.
- [Release notes](https://github.com/actions/setup-dotnet/releases)
- [Commits](https://github.com/actions/setup-dotnet/compare/v4...v5)

---
updated-dependencies:
- dependency-name: actions/setup-dotnet
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/buildtest.yaml

@@ -12,7 +12,7 @@ jobs:
         with:
           fetch-depth: 0
       - name: Setup dotnet
-        uses: actions/setup-dotnet@v4
+        uses: actions/setup-dotnet@v5
         with:
           dotnet-version: |
            8.0.x
@@ -48,7 +48,7 @@ jobs:
       - name: Add msbuild to PATH
         uses: microsoft/setup-msbuild@v2
       - name: Setup dotnet SDK
-        uses: actions/setup-dotnet@v4
+        uses: actions/setup-dotnet@v5
         with:
           dotnet-version: '9.0.x'
       - name: Restore nugets (msbuild)
@@ -63,7 +63,7 @@ jobs:
         with:
           fetch-depth: 0
       - name: Setup dotnet
-        uses: actions/setup-dotnet@v4
+        uses: actions/setup-dotnet@v5
         with:
           dotnet-version: |
            8.0.x