ci: Install .NET 10 Preview in site extension release workflow (#3291)

Author: tippmar-nr

.github/workflows/siteextension_release.yml

@@ -34,7 +34,13 @@ jobs:
         uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           fetch-depth: 0
-          
+
+      - name: Setup .NET 10 Preview
+        uses: actions/setup-dotnet@d4c94342e560b34958eacfc5d055d21461ed1c5d # v5.0.0
+        with:
+          dotnet-version: '10.0.x'
+          dotnet-quality: 'preview'
+
       - name: Add msbuild to PATH
         uses: microsoft/setup-msbuild@6fb02220983dee41ce7ae257b6f4d8f9bf5ed4ce # v2.0.0