github actions: update python to 3.11

Blocker speced/bikeshed#2386 is resolved.

Author: Thiago Perrotta

.github/workflows/test.yml

@@ -13,8 +13,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-python@v3
         with:
-          # Python 3.11 is broken: https://github.com/tabatkins/bikeshed/issues/2386
-          python-version: "3.10"
+          python-version: "3.11"
       - name: Build spec without warnings
         run: ./scripts/build.sh --install
   cddl: