Fixed prelease step

Author: koenbeuk

.github/workflows/build.yml

@@ -46,7 +46,7 @@ jobs:
       - name: Setup .NET
         uses: actions/setup-dotnet@v1
         with:
-          dotnet-version: 7.0.x
+          dotnet-version: 8.0.x
       - name: Pack
         run: | 
           dotnet pack -v normal -c Debug --include-symbols --include-source -p:PackageVersion=4.0.0-pre-$GITHUB_RUN_ID -o nupkg