remove 3.6

Author: fangq

.github/workflows/run_test.yml

@@ -7,7 +7,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["2.7", "3.6", "3.7", "3.8", "3.9", "3.10", "3.11"]
+        python-version: ["2.7", "3.7", "3.8", "3.9", "3.10", "3.11"]
 
     steps:
       - uses: actions/checkout@v3