Ensure sentence triggers are only checked once

[synesthesiam]

Breaking change

Proposed change

Fixes a small bug mentioned here: #129058 (comment)

When using the default conversation agent, sentence triggers were being checked twice: once in the pipeline code and again inside the agent code. They were not being triggered twice, however.

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• Dependency upgrade
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• This PR fixes or closes issue: fixes #
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[home-assistant]

Hey there @balloob, mind taking a look at this pull request as it has been labeled with an integration (assist_pipeline) you are listed as a code owner for? Thanks!

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