pg_isready --dbname option is broken. So it should not be in the manual

The following documentation comment has been logged on the website:

Page: https://www.postgresql.org/docs/16/app-pg-isready.html
Description:

the --dbname option in pg_isready seems not to work propperly. the tool
returns 'ok' as long as the cluster itselft is running, no matter how wrong
the bdname might be.

as this seems to be a ~10 year old misbehaviour as per the below thread I
think it should be removed from the manual.

https://www.postgresql.org/message-id/flat/52840D38.9070604%40agliodbs.com