CI - fix windows shell escaping

Author: tmenier

.github/workflows/ci.yml

@@ -38,4 +38,4 @@ jobs:
         run: dotnet restore
 
       - name: Test
-        run: dotnet test --framework ${{ matrix.framework }} -c Release /p:CollectCoverage=true /p:Threshold=80 /p:Include=\"[Flurl]*,[Flurl.Http]*,[Flurl.Http.Newtonsoft]*\" /p:Exclude="[*]*.GeneratedExtensions"
+        run: dotnet test --framework ${{ matrix.framework }} -c Release /p:CollectCoverage=true /p:Threshold=80 /p:Include="[Flurl]*,[Flurl.Http]*,[Flurl.Http.Newtonsoft]*" /p:Exclude="[*]*.GeneratedExtensions"