Bump microsoft/setup-msbuild from 1.3 to 2 (#210)

Bumps [microsoft/setup-msbuild](https://github.com/microsoft/setup-msbuild) from 1.3 to 2.
- [Release notes](https://github.com/microsoft/setup-msbuild/releases)
- [Changelog](https://github.com/microsoft/setup-msbuild/blob/main/building-release.md)
- [Commits](microsoft/setup-msbuild@v1.3...v2)

---
updated-dependencies:
- dependency-name: microsoft/setup-msbuild
  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/dotnet.yml

@@ -18,7 +18,7 @@ jobs:
         dotnet-version: '5.0.x'
     - name: Add msbuild to PATH
       if: matrix.os == 'windows-latest'
-      uses: microsoft/setup-msbuild@v1.3
+      uses: microsoft/setup-msbuild@v2
     - name: Build console app
       run: dotnet build SharpXMPP.Console
     - name: Build WPF app