Upgrade to latest python releases

Author: quantum5

.github/workflows/build.yml

@@ -5,7 +5,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [ 3.6.12, 3.7.9, 3.8.6, 3.9.0 ]
+        python-version: [ 3.6.15, 3.7.12, 3.8.12, 3.9.7 ]
         arch: [ amd64, aarch64 ]
     steps:
       - uses: actions/checkout@v2