Enable mypy

.github/workflows/mypy.yml

@@ -0,0 +1,39 @@
+name: mypy
+
+on:
+  push:
+  pull_request:
+
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+jobs:
+  test-linux:
+    runs-on: ubuntu-20.04
+
+    steps:
+      # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
+      - uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: "3.10"
+          cache: "pip"
+
+      # This is needed for pygobject-stubs
+      - name: Install system packages
+        run: |
+          sudo apt install libgirepository1.0-dev
+
+      - name: Install dependencies
+        run: |
+          pip install --upgrade pip wheel
+          pip install -r requirements.txt -r requirements-tests.txt
+          pip install -e .
+
+      - name: Run mypy
+        run: |
+          mypy deluge/