Remove outdated python3.6 from CI

Author: drons

.github/workflows/build.yml

@@ -8,7 +8,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest]
-        python-version: ["3.6", "3.7", "3.8", "3.9", "3.10"]
+        python-version: ["3.7", "3.8", "3.9", "3.10"]
     steps:
       - uses: actions/checkout@v3
       - uses: actions/setup-python@v4