Updated CI

Author: jamesmcroft

.github/workflows/ci.yml

@@ -55,11 +55,8 @@ jobs:
       with:
         dotnet-version: 6.0.x
 
-    - name: Setup NuGet
-      uses: NuGet/setup-nuget@v1.0.5
-
     - name: Restore dependencies
-      run: nuget restore $SOLUTION
+      run: dotnet restore $SOLUTION
 
     - name: Setup MSBuild
       uses: microsoft/setup-msbuild@v1.0.2