Install .NET runtime on GitHub Actions runner

.github/workflows/ci.yml

@@ -58,6 +58,28 @@ jobs:
         uses: actions/setup-dotnet@v6.0.0
         with:
           global-json-file: global.json
+      - name: Determine runtime version
+        shell: pwsh
+        run: |
+          # Read settings from Custom.Build.props
+          [xml]$xml = Get-Content ./src/Custom.Build.props
+          $runtimeVersion = $xml.selectNodes('/Project/PropertyGroup/RuntimeFrameworkVersion').InnerText
+          if (-not ($runtimeVersion)) {
+            throw "Missing RuntimeFrameworkVersion setting in Custom.Build.props"
+          }
+          echo "RuntimeVersion=$runtimeVersion" | Out-File -FilePath $Env:GITHUB_ENV -Encoding utf-8 -Append
+      - name: Install .NET Runtime on Windows
+        if: matrix.os-name == 'Windows'
+        run: |
+          ./tools/dotnet-install.ps1 -SkipNonVersionedFiles -InstallDir "C:\Program Files\dotnet" -Runtime dotnet -Version ${{ env.RuntimeVersion }}
+          ./tools/dotnet-install.ps1 -SkipNonVersionedFiles -InstallDir "C:\Program Files\dotnet" -Runtime aspnetcore -Version ${{ env.RuntimeVersion }}
+          ./tools/dotnet-install.ps1 -SkipNonVersionedFiles -InstallDir "C:\Program Files\dotnet" -Runtime windowsdesktop -Version ${{ env.RuntimeVersion }}
+      - name: Install .NET Runtime on Linux
+        if: matrix.os-name == 'Linux'
+        shell: bash
+        run: |
+          ./tools/dotnet-install.sh --skip-non-versioned-files --install-dir /usr/share/dotnet --runtime dotnet --version ${{ env.RuntimeVersion }}
+          ./tools/dotnet-install.sh --skip-non-versioned-files --install-dir /usr/share/dotnet --runtime aspnetcore --version ${{ env.RuntimeVersion }}
       - name: Select test projects
         id: select
         run: ./tools/select-test-projects.ps1 -Category ${{ matrix.test-category }}
@@ -80,7 +102,7 @@ jobs:
           memory: 8GB
       # there is an issue with az cli and python 3.14, so for now we need to pin it
       # once the issue is resolved it should be able to be re-floated
-      # https://github.com/Azure/azure-cli/issues/32980. 
+      # https://github.com/Azure/azure-cli/issues/32980.
       # This can be removed once https://github.com/Azure/azure-cli/issues/32869 is supported.
       - name: Set Python 3.13 (Linux)
         if: matrix.os-name == 'Linux' && matrix.test-category == 'AzureServiceBus'