internal/ratelimit: Do not silently ignore errors, log them!

Created by: indradhanush

The Monitor.Update method silently returns on error. We should log errors at the very least. Ideally, the Update method should return the error so that callers can decide how to react.

Future work: We should have some alerts configured for ratelimit update errors as respecting ratelimits is very important and we should know of any unprecendented errors.

Test plan

No change in functionality. Adds error logging only