fix(ipc): retry proc acquisition when spawns fail

[rosetta-livekit-bot]

Summary

Fixes #5868. When every worker process fails to initialize, launch_job previously hung forever on _warmed_proc_queue.get() because nothing was ever put on the queue, and the 3-attempt retry loop was unreachable.

Split the responsibility: _acquire_proc now owns the wait-for-a-warmed-process loop. It races queue.get() against every in-flight spawn task and only retries once all in-flight spawns settle without producing a proc — so peer spawns still in flight don't burn a retry attempt. After MAX_ACQUIRE_ATTEMPTS such cycles, it raises a RuntimeError. launch_job keeps its own 3-attempt budget for post-acquire launch failures (the original retry semantics, untouched).

Alternative considered

#5871 uses None sentinels on _warmed_proc_queue to unblock waiters when a spawn fails. Two issues with that approach:

1. It wakes too eagerly — a sentinel is pushed on each individual spawn failure, even though peer spawns may still succeed, burning a retry attempt.
2. The retry doesn't trigger a fresh spawn — on loop-back the queue isn't empty (it has more None sentinels), so launch_job consumes another sentinel without ever requesting a new process. MAX_ATTEMPTS=3 becomes "fail 3 sentinels and give up".

[changeset-bot]

🦋 Changeset detected

Latest commit: 93866f2

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 33 packages

Name	Type
@livekit/agents	Patch
@livekit/agents-plugin-anam	Patch
@livekit/agents-plugin-assemblyai	Patch
@livekit/agents-plugin-baseten	Patch
@livekit/agents-plugin-bey	Patch
@livekit/agents-plugin-cartesia	Patch
@livekit/agents-plugin-cerebras	Patch
@livekit/agents-plugin-deepgram	Patch
@livekit/agents-plugin-elevenlabs	Patch
@livekit/agents-plugin-fishaudio	Patch
@livekit/agents-plugin-google	Patch
@livekit/agents-plugin-hedra	Patch
@livekit/agents-plugin-hume	Patch
@livekit/agents-plugin-inworld	Patch
@livekit/agents-plugin-lemonslice	Patch
@livekit/agents-plugin-liveavatar	Patch
@livekit/agents-plugin-livekit	Patch
@livekit/agents-plugin-minimax	Patch
@livekit/agents-plugin-mistral	Patch
@livekit/agents-plugin-mistralai	Patch
@livekit/agents-plugin-neuphonic	Patch
@livekit/agents-plugin-openai	Patch
@livekit/agents-plugin-perplexity	Patch
@livekit/agents-plugin-phonic	Patch
@livekit/agents-plugin-resemble	Patch
@livekit/agents-plugin-rime	Patch
@livekit/agents-plugin-runway	Patch
@livekit/agents-plugin-sarvam	Patch
@livekit/agents-plugin-silero	Patch
@livekit/agents-plugin-tavus	Patch
@livekit/agents-plugins-test	Patch
@livekit/agents-plugin-trugen	Patch
@livekit/agents-plugin-xai	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no bugs or issues to report.