Don't run Python 3.6 test with GitHub actions

But this version is still supported and can be tested locally with tox.

Author: Cito

.github/workflows/test-package.yml

@@ -9,7 +9,7 @@ jobs:
     strategy:
       max-parallel: 4
       matrix:
-        python-version: ['3.6', '3.7', '3.8', '3.9', '3.10', '3.11', 'pypy3']
+        python-version: ['3.7', '3.8', '3.9', '3.10', '3.11', 'pypy3']
 
     steps:
     - uses: actions/checkout@v2
@@ -20,7 +20,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install .[tests]
+        pip install .[tests] --use-pep517
     - name: Lint with flake8
       if: matrix.python-version == '3.10'
       run: |