Fix multitask transcribe override_config timestamps handling

[gmartini2000]

One of the checks appears to be failing due to the workflow not being able to find the PR head commit from the fork:

• Unable to locate commit sha: 3bfbcb6
• Unable to find merge base
• Suggestion in logs mentions setting actions/checkout repository to ${{ github.event.pull_request.head.repo.full_name }} for forked PRs

This looks like a workflow checkout/diff issue rather than a code issue on this PR.

Important

The Update branch button must only be pressed in very rare occassions.
An outdated branch is never blocking the merge of a PR.
Please reach out to the automation team before pressing that button.

What does this PR do ?

Fixes an issue where EncDecMultiTaskModel.transcribe() overwrites the timestamps value provided through override_config when the timestamps parameter is left as its default (None). The fix ensures that timestamps defined in MultiTaskTranscriptionConfig are preserved unless the timestamps parameter is explicitly provided.

Collection: ASR

Changelog

• Fixed logic in EncDecMultiTaskModel.transcribe() to prevent override_config.timestamps from being overwritten by the default timestamps=None parameter.
• Added a conditional guard so that timestamps are only overridden when explicitly provided.
• Added a regression test to ensure timestamps set via MultiTaskTranscriptionConfig are preserved when using override_config.

Usage

Example demonstrating usage of override_config with timestamps preserved.

from nemo.collections.asr.models import ASRModel
from nemo.collections.asr.models.aed_multitask_models import MultiTaskTranscriptionConfig

model = ASRModel.restore_from("model.nemo")

config = MultiTaskTranscriptionConfig(
    batch_size=4,
    return_hypotheses=True,
    timestamps=True,
)

outputs = model.transcribe(["audio.wav"], override_config=config)

print(outputs[0].timestamp)

GitHub Actions CI

The Jenkins CI system has been replaced by GitHub Actions self-hosted runners.

The GitHub Actions CI will run automatically when the "Run CICD" label is added to the PR.
To re-run CI remove and add the label again.
To run CI on an untrusted fork, a NeMo user with write access must first click "Approve and run".

Before your PR is "Ready for review"

Pre checks:

• Make sure you read and followed Contributor guidelines
• Did you write any new necessary tests?
• Did you add or update any necessary documentation?
• Does the PR affect components that are optional to install? (Ex: Numba, Pynini, Apex etc)
  • Reviewer: Does the PR have correct import guards for all optional libraries?

PR Type:

• New Feature
• Bugfix
• Documentation

If you haven't finished some of the above items you can still open "Draft" PR.

Who can review?

Anyone in the community is free to review the PR once the checks have passed.
Contributor guidelines contains specific people who can review PRs to various areas.

Additional Information

• Related to Update docs for NeMo Framework #8596