fix: install job should not use python 3.5 anymore

Author: jerem

.github/workflows/install.yml

@@ -9,7 +9,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [3.5, 3.6, 3.7, 3.8]
+        python-version: [3.6, 3.7, 3.8, 3.9]
     steps:
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v1