Remove extra .NET setup.

Author: jonsimantov

.github/workflows/build_windows.yml

@@ -65,10 +65,6 @@ jobs:
       - name: Support longpaths
         run: git config --system core.longpaths true
 
-      - uses: actions/setup-dotnet@v4
-        with:
-          dotnet-version: '4.5.x'
-
       - name: Setup python
         uses: actions/setup-python@v4
         with: