Exclude Python 3.6 on macOS

Author: ivankravets

.github/workflows/main.yml

@@ -9,6 +9,9 @@ jobs:
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
         python-version: [3.6, 3.7, 3.8, 3.9]
+        exclude:
+          - os: macos-latest
+            python-version: "3.6"
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v2