ci: drop support for Python 3.6

Author: owenvoke

.github/workflows/test.yml

@@ -8,13 +8,13 @@ jobs:
 
     strategy:
       matrix:
-        python-version: ['3.6', '3.7', '3.8', '3.9', '3.10', 'pypy3']
+        python-version: ['3.7', '3.8', '3.9', '3.10', 'pypy3.9']
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
 
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v1
+      uses: actions/setup-python@v4
       with:
         python-version: ${{ matrix.python-version }}