nesati

## Description `_timeline_cache_timestamp` is uninitalised in `PlexSonosClient`. I added a line that initilises it the same way the base `PlexClient` does. Fixes #1523 ## Type of change Please delete options...

### Describe the Bug ``` Traceback (most recent call last): File "/home/user/bug_report.py", line 10, in for timeline in client.timelines(): ~~~~~~~~~~~~~~~~^^ File "/home/user/miniconda3/envs/shadowloop/lib/python3.13/site-packages/plexapi/client.py", line 578, in timelines if t - self._timeline_cache_timestamp...