PYTHON-3679 Support mypy 1.2

Author: ShaneHarvey

.github/workflows/test-python.yml

@@ -58,7 +58,7 @@ jobs:
           cache-dependency-path: 'setup.py'
       - name: Install dependencies
         run: |
-          python -m pip install -U pip mypy==0.990
+          python -m pip install -U pip mypy==1.2
           pip install -e ".[zstd, encryption, ocsp]"
       - name: Run mypy
         run: |