Simplify the CI tests using the Makefile

.github/workflows/mypy.yml

@@ -0,0 +1,27 @@
+name: Mypy
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  mypy_py3:
+    name: Mypy check
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: Setup Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: 3.9
+          cache: 'pip'
+      - name: Checkout
+        uses: actions/checkout@master
+      - name: Install Dependencies
+        run: |
+          pip install mypy
+      - name: mypy
+        run: |
+          make mypy