document nuances of `replayDeletion: true` in Usage API

### What's Missing?

The Usage API has been promoted to Beta and is on by default in v1.19.0. We had hoped to set `replayDeletion: true` as the default because of the performance boost during resource cleanup, but after discovering some potentially damaging and undesirable behavior, we decided to not make this the default. @turkenh captured this decision and behavior in:
https://github.com/crossplane/crossplane/issues/6140#issuecomment-2538629314

We should capture this in the Usage docs page, so users can make an informed decision about when to use `replayDeletion` in their environment.
https://docs.crossplane.io/master/concepts/usages/#replay-blocked-deletion-attempt