Upgrade CodeQl to use setup-dotnet to v3.

Author: mjpt777

.github/workflows/codeql.yml

@@ -117,7 +117,7 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-nuget-
       - name: Setup dotnet
-        uses: actions/setup-dotnet@v2
+        uses: actions/setup-dotnet@v3
         with:
           dotnet-version: ${{ matrix.dotnet }}