fix globaljson nonsense

Author: TheAngryByrd

.github/workflows/build.yml

@@ -71,16 +71,19 @@ jobs:
 
     # setup .NET per test session
     - name: Setup .NET
+      id : setup-dotnet
       uses: actions/setup-dotnet@v3
       with:
-        include-prerelease: ${{ matrix.include-prerelease }}
         global-json-file: ${{ matrix.global-json-file }}
         dotnet-version: ${{ matrix.dotnet-version }}
 
     # remove global.json so that the env configuration takes precedence
     - name: Purge global.json
       run: rm global.json
 
+    - name: Create global.json
+      run: dotnet new globaljson --sdk-version '${{ steps.setup-dotnet.outputs.dotnet-version }}' --roll-forward latestMinor
+
     # let's make sure we're on the version we think we are.
     - name: Announce .NET version
       run: dotnet --info