Update .NET version to 8.0 for Custom Elements publish

Changed the .NET target framework for the Custom Elements project from 7.0 to 8.0 in the GitHub workflow. This ensures compatibility with the latest runtime features and improvements.

.github/workflows/packages.yml

@@ -73,7 +73,7 @@ jobs:
       - name: Pack nuget packages
         run: dotnet pack Elsa.Studio.sln --configuration Release /p:Version=${VERSION} /p:PackageOutputPath=$(pwd)/packages/nuget
       - name: Publish Custom Elements packages # This generates client assets that we then package as an NPM package.
-        run: dotnet publish ./src/hosts/Elsa.Studio.Host.CustomElements --configuration Release -o ./packages/wasm /p:Version=${VERSION} -f net7.0
+        run: dotnet publish ./src/hosts/Elsa.Studio.Host.CustomElements --configuration Release -o ./packages/wasm /p:Version=${VERSION} -f net8.0
 
       # Pack npm wasm package
       - name: Pack elsa-studio-wasm npm package