remove windows; only test on main branch

Author: Myse1f

.github/workflows/test.yml

@@ -1,11 +1,19 @@
 name: test
-on: [push, pull_request]
+on
+  # Trigger the workflow on push or pull request,
+  # but only for the main branch
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
 
 jobs:
   test:
     strategy:
       matrix:
-        os: [ubuntu-latest, macos-latest, windows-latest]
+        os: [ubuntu-latest, macos-latest]
         python-version: [3.6, 3.7, 3.8, 3.9]
     runs-on: ${{ matrix.os }}
     steps: