[gh actions] Add Py 3.11 to Linux matrix

Author: mpsonntag

.github/workflows/run-tests.yml

@@ -13,7 +13,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        python-version: ["3.8", "3.9", "3.10"]
+        python-version: ["3.8", "3.9", "3.10", "3.11"]
     steps:
       - uses: actions/checkout@v2
       - name: Setup Python ${{ matrix.python-version }}