fix: support newer onnx-asr Nemo import path

[VooDisss]

What was broken

speaches failed to start when onnx-asr 0.11+ was installed.

Startup crashed while importing the Parakeet executor with:

ImportError: cannot import name 'NemoConformerTdt' from 'onnx_asr.models'

The current code assumes NemoConformerTdt is available from:

onnx_asr.models

That is no longer true in newer onnx-asr releases, where the class is exposed from:

onnx_asr.models.nemo

What this changes

This patch keeps the existing import for older versions and adds a fallback for newer ones.

• first try: from onnx_asr.models import NemoConformerTdt
• fallback to: from onnx_asr.models.nemo import NemoConformerTdt

What this fixes

• restores app startup when newer onnx-asr versions are installed
• keeps compatibility with the older import path used by the current locked dependency set
• avoids forcing users to downgrade onnx-asr just to run the server

Why this matters

This failure happens before the app is fully up, so users hit a hard startup error even if they are not actively using the Parakeet path.

The fallback keeps the change narrow and makes startup more tolerant of dependency drift.