Add option for a min delay between playouts

[martin-purplefish]

My agent occasionally wants to play audio immediately after it's done playing - this is to allow for a minimum gap between the two to avoid awkward responses. I've found a value around 0.7 is good, but I wanted to leave it at 0 to avoid a behavior change.

[changeset-bot[bot]]

🦋 Changeset detected

Latest commit: 95ceeb67b65f0e540f67420bb189ccb0ba472fbe

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

This PR includes changesets to release 1 package

Name	Type
livekit-agents	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

[martin-purplefish]

PTAL @davidzhao @theomonnom