CI: Disable OSX builds.

They don't want to do the network integration tests.

.github/workflows/ci.yml

@@ -6,7 +6,8 @@ jobs:
   test-units:
     strategy:
       matrix:
-        os: [ubuntu-latest, macos-latest]
+        #os: [ubuntu-latest, macos-latest]
+        os: [ubuntu-latest]
     runs-on: ${{ matrix.os }}
 
     steps: