upgrade SDK to 3.1.102

Author: adamralph

.github/workflows/ci.yml

@@ -17,7 +17,7 @@ jobs:
     steps:
     - uses: actions/setup-dotnet@bb95ce727fd49ec1a65933419cc7c91747785302
       with:
-        dotnet-version: '3.1.100'
+        dotnet-version: '3.1.102'
     - run: dotnet --info
     - uses: actions/checkout@af513c7a016048ae468971c52ed77d9562c7c819
     - if: contains(matrix.runs-on, 'windows')