gh-104504: Run mypy on cases_generator in CI (and blacken the code) (gh-108090)

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

.github/dependabot.yml

@@ -13,7 +13,7 @@ updates:
           - "version-update:semver-minor"
           - "version-update:semver-patch"
   - package-ecosystem: "pip"
-    directory: "/Tools/clinic/"
+    directory: "/Tools/"
     schedule:
       interval: "monthly"
     labels:

.github/workflows/mypy.yml

@@ -8,6 +8,7 @@ on:
   pull_request:
     paths:
       - "Tools/clinic/**"
+      - "Tools/cases_generator/**"
       - ".github/workflows/mypy.yml"
   workflow_dispatch:
 
@@ -25,15 +26,18 @@ concurrency:
 
 jobs:
   mypy:
-    name: Run mypy on Tools/clinic/
+    strategy:
+      matrix:
+        target: ["Tools/cases_generator", "Tools/clinic"]
+    name: Run mypy on ${{ matrix.target }}
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
       - uses: actions/checkout@v3
       - uses: actions/setup-python@v4
         with:
-          python-version: "3.x"
+          python-version: "3.11"
           cache: pip
-          cache-dependency-path: Tools/clinic/requirements-dev.txt
-      - run: pip install -r Tools/clinic/requirements-dev.txt
-      - run: mypy --config-file Tools/clinic/mypy.ini
+          cache-dependency-path: Tools/requirements-dev.txt
+      - run: pip install -r Tools/requirements-dev.txt
+      - run: mypy --config-file ${{ matrix.target }}/mypy.ini