chore: add warning mypy takes a while, fix ruff, types #342

Job	Run time
config-deploy	16s
backend-ci / backend-ci	52s
build-db (production) / build-db	0s
build-kv (localdev) / build-kv	38s
build-db (staging) / build-db	35s
build-db (localdev) / build-db	55s
build-kv (production) / build-kv	0s
build-kv (staging) / build-kv	25s
build-server (localdev) / build-server	1m 11s
build-server (production) / build-server	0s
build-server (staging) / build-server	21s
	5m 13s

Provide feedback