Bump plexapi from 4.17.2 to 4.18.0

Bumps [plexapi](https://github.com/pushingkarmaorg/python-plexapi) from 4.17.2 to 4.18.0.
- [Release notes](https://github.com/pushingkarmaorg/python-plexapi/releases)
- [Commits](pushingkarmaorg/python-plexapi@4.17.2...4.18.0)

---
updated-dependencies:
- dependency-name: plexapi
  dependency-version: 4.18.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

requirements-test.txt

@@ -1,7 +1,7 @@
 beautifulsoup4==4.14.3
 ruff==0.15.1
 mypy==1.19.1
-PlexAPI==4.17.2
+PlexAPI==4.18.0
 pylint==4.0.4
 rstcheck==6.2.5
 types-beautifulsoup4==4.12.0.20250516