livekit-agents@1.5.5

## What's Changed
* feat(inference): STT diarization capabilities and speaker_id on TimedString, add xAI TTS support for inference by @russellmartin-livekit in https://github.com/livekit/agents/pull/5438
* [inworld] timed_string to no longer have trailing spaces by @ianbbqzy in https://github.com/livekit/agents/pull/5470
* fix(examples): update e2ee.py to use encryption kwarg and env var by @aryeila in https://github.com/livekit/agents/pull/5469
* chore(deps): update dependency pillow to v12.2.0 [security] by @renovate[bot] in https://github.com/livekit/agents/pull/5440
* fix(tests): update preemptive_generation mock to use dict by @longcw in https://github.com/livekit/agents/pull/5468
* fix(telemetry): bound OTel provider shutdown to avoid watchdog kills by @theomonnom in https://github.com/livekit/agents/pull/5471
* feat(assemblyai): log connection lifecycle, silence, and session correlators by @dlange-aai in https://github.com/livekit/agents/pull/5476
* fix: strip markdown emphasis adjacent to punctuation by @carschandler in https://github.com/livekit/agents/pull/5481
* (aws realtime): add expiry check for cached credentials by @tinalenguyen in https://github.com/livekit/agents/pull/5485
* (hedra): note deprecation in readme by @tinalenguyen in https://github.com/livekit/agents/pull/5475
* (deepgram sttv2): add flux-general-multi support by @tinalenguyen in https://github.com/livekit/agents/pull/5486
* (xai stt): expose endpointing param to user by @tinalenguyen in https://github.com/livekit/agents/pull/5493
* fix(room-io): ownership-aware FrameProcessor lifecycle management by @longcw in https://github.com/livekit/agents/pull/5467
* (openai responses): drop prompt_cache_retention in received responses by @tinalenguyen in https://github.com/livekit/agents/pull/5502
* feat(avatar): add AvatarSession base class, warn on sync mis-wire by @longcw in https://github.com/livekit/agents/pull/5499
* livekit-agents@1.5.5 by @github-actions[bot] in https://github.com/livekit/agents/pull/5503

## New Contributors
* @carschandler made their first contribution in https://github.com/livekit/agents/pull/5481

**Full Changelog**: https://github.com/livekit/agents/compare/livekit-agents@1.5.4...livekit-agents@1.5.5