Let's try to cleanup before building

.github/workflows/dotnetcore.yml

@@ -16,4 +16,6 @@ jobs:
     - name: Test
       run: dotnet test PSDTextTests/
     - name: Build
-      run: dotnet build --configuration Release --framework netcoreapp3.1 PSDText/
+      run:
+        dotnet clean --configuration Release
+        dotnet build --configuration Release --framework netcoreapp3.1 PSDText/