also remove windows test in PR testing temporarily

Author: rodrigomha

.github/workflows/pr_testing.yml

@@ -12,7 +12,7 @@ jobs:
       matrix:
         julia-version: ['1']
         julia-arch: [x64]
-        os: [ubuntu-latest, windows-latest, macOS-latest]
+        os: [ubuntu-latest, macOS-latest]
 
     steps:
       - uses: actions/checkout@v2