build only ubuntu

Author: bkoelman

.github/workflows/dotnet.yml

@@ -35,7 +35,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, windows-latest, macos-latest]
+        #os: [ubuntu-latest, windows-latest, macos-latest]
+        os: [ubuntu-latest]
     runs-on: ${{ matrix.os }}
     steps:
     - name: Setup PostgreSQL