First draft of CI

.forgejo/workflows/lint.yaml

@@ -0,0 +1,25 @@
+---
+on: [push]
+
+name: Lint
+
+jobs:
+  lint:
+    name: MyPy
+    runs-on: docker
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      # TODO: Replace with working action
+      - name: Set up Python environment
+        run: |
+          curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py
+          python3 get-pip.py
+          python3 -m pip install virtualenv
+          python3 -m virtualenv venv
+          source venv/bin/activate
+          pip install -r requirements.txt
+      - name: Type-check
+        run: |
+          source venv/bin/activate
+          mypy *.py