More pipeline fixes

Author: macsux

.github/workflows/dotnet.yaml

@@ -23,7 +23,8 @@ jobs:
         uses: actions/setup-dotnet@v1
         with:
           dotnet-version: 3.1.200
-      - name: .net SxS
+      - name: Setup side by side .NET SDKs on Linux & Mac
+        if: matrix.os != 'windows-latest'
         run: |
           rsync -a ${DOTNET_ROOT/3.1.200/2.1.300}/* $DOTNET_ROOT/