fix(python): downgrade to latest Python 3.13 (#523)

This app's dependencies do not work with Python 3.14's new async event loop changes, so I am setting the upper version limit to 3.13.

Reviewed-on: #523

compose.yaml

@@ -0,0 +1,7 @@
+services:
+  app:
+    build:
+      context: .
+      dockerfile: Dockerfile
+    restart: unless-stopped
+    env_file: .env