Add missing type hints to tests.config. (#14681)

changelog.d/14681.misc

mypy.ini

synapse/config/cache.py

synapse/util/caches/lrucache.py

tests/config/test___main__.py

tests/config/test_background_update.py

tests/config/test_base.py

tests/config/test_cache.py

tests/config/test_database.py

tests/config/test_generate.py

tests/config/test_load.py

tests/config/test_ratelimiting.py

tests/config/test_registration_config.py

tests/config/test_room_directory.py

tests/config/test_server.py

tests/config/test_tls.py

tests/config/test_util.py

tests/config/utils.py