ci: use Python 3.12 for type tests

Author: daviddrysdale

.github/workflows/typing.yml

@@ -10,15 +10,16 @@ jobs:
     steps:
       - uses: actions/checkout@629c2de402a417ea7690ca6ce3f33229e27606a5 # v2
 
-      - name: Set up latest Python 3
+      - name: Set up Python 3.12
         uses: actions/setup-python@f38219332975fe8f9c04cca981d674bf22aea1d3 # v2
         with:
-          python-version: 3
+          python-version: 3.12
 
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
           pip install mypy==0.921 types-protobuf==3.19.21
+          pip install typed-ast==1.5.5
 
       - name: Execute run_stubtest.py
         run: |
@@ -31,10 +32,10 @@ jobs:
     steps:
       - uses: actions/checkout@629c2de402a417ea7690ca6ce3f33229e27606a5 # v2
 
-      - name: Set up latest Python 3
+      - name: Set up Python 3.12
         uses: actions/setup-python@f38219332975fe8f9c04cca981d674bf22aea1d3 # v2
         with:
-          python-version: 3
+          python-version: 3.12
 
       - name: Install dependencies
         run: |