Specify specific python version

Previously, we were testing with the most recent, but our tox config
didn't yet have 3.11, causing no tests to run.

Author: oschwald

.github/workflows/address-sanitizer.yml

@@ -25,7 +25,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v4
         with:
-          python-version: 3.x
+          python-version: 3.11
 
       - name: Install dependencies
         run: |

.github/workflows/clang-analyzer.yml

@@ -20,7 +20,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v4
         with:
-          python-version: 3.x
+          python-version: 3.11
 
       - name: Build and run analyzer
         run: CFLAGS="-Werror -Wall -Wextra" scan-build --status-bugs python setup.py build