remove

Author: firewave

.github/workflows/CI-cygwin.yml

@@ -9,7 +9,7 @@ jobs:
 
     strategy:
       matrix:
-        os: [ubuntu-18.04, ubuntu-20.04, macos-10.15]
+        os: [ubuntu-20.04]
       fail-fast: false # Prefer quick result
 
     runs-on: ${{ matrix.os }}