JNI replace llama runner with llm text runner

[kirklandsign]

Summary

Use the API from extension/llm

Test plan

CI

cc @cbilgin

[pytorch-bot]

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❌ 1 New Failure

As of commit 49c037f with merge base e4afd0a ():

NEW FAILURE - The following job has failed:

• Build documentation / build (buck2) / Build doc (gh)
  At least one of the pre-conditions you specified did not hold

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