Update build solution path in GitHub Actions workflow

Changed the msbuild command to point to "source/Plugins.sln" instead of "source/Plugins.Filter.slnf". This ensures the correct solution file is used during the build process in the workflow.

.github/workflows/main.yml

@@ -39,7 +39,7 @@ jobs:
 
       # Build the solution
       - name: Build solution
-        run: msbuild "source\Plugins.Filter.slnf" /p:Configuration=Release
+        run: msbuild "source\Plugins.sln" /p:Configuration=Release
 
       # Copy dll to target directory
       - name: Create archives