Added mypy to scripts and workflow, and some first annotations for celerywyrm

.github/workflows/mypy.yml

@@ -0,0 +1,50 @@
+name: Mypy
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: Set up Python 3.9
+      uses: actions/setup-python@v4
+      with:
+        python-version: 3.9
+    - name: Install Dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install -r requirements.txt
+    - name: Analysing the code with mypy
+      env:
+        SECRET_KEY: beepbeep
+        DEBUG: false
+        USE_HTTPS: true
+        DOMAIN: your.domain.here
+        BOOKWYRM_DATABASE_BACKEND: postgres
+        MEDIA_ROOT: images/
+        POSTGRES_PASSWORD: hunter2
+        POSTGRES_USER: postgres
+        POSTGRES_DB: github_actions
+        POSTGRES_HOST: 127.0.0.1
+        CELERY_BROKER: ""
+        REDIS_BROKER_PORT: 6379
+        REDIS_BROKER_PASSWORD: beep
+        USE_DUMMY_CACHE: true
+        FLOWER_PORT: 8888
+        EMAIL_HOST: "smtp.mailgun.org"
+        EMAIL_PORT: 587
+        EMAIL_HOST_USER: ""
+        EMAIL_HOST_PASSWORD: ""
+        EMAIL_USE_TLS: true
+        ENABLE_PREVIEW_IMAGES: false
+        ENABLE_THUMBNAIL_GENERATION: true
+        HTTP_X_FORWARDED_PROTO: false
+      run: |
+        mypy bookwyrm celerywyrm