link to docs on starting ephemeral server

[zzstoatzz]

closes #15597

open to suggestions on these exact log messages

In [1]: from prefect import flow

In [2]: @flow
   ...: def f(): pass

In [3]: f()
16:16:42.932 | INFO    | prefect - Starting ephemeral server on http://127.0.0.1:8095 - see https://docs.prefect.io/3.0/manage/self-host#self-host-a-prefect-server for more information on running a dedicated Prefect server.
16:16:45.015 | INFO    | prefect.engine - Created flow run 'khaki-wildcat' for flow 'f'
16:16:45.066 | INFO    | Flow run 'khaki-wildcat' - Finished in state Completed()

In [4]: exit
16:16:48.660 | INFO    | prefect - Stopping ephemeral server on http://127.0.0.1:8095

[codspeed-hq]

CodSpeed Performance Report

Merging #15636 will not alter performance

_{Comparing more-informative-epehemeral-server-log (88fb2f0) with main (bc0a0c8)}

Summary

✅ 3 untouched benchmarks