fix: resolve dataset preparation failure caused by upstream framework update

[Fahmid-Arman]

What type of PR is this?
/kind bug

What this PR does / why we need it:
This PR resolves a backward-compatibility break in the dataset preparation logic that caused benchmarkingjob failures across multiple legacy examples.

• Root Cause: A prior framework refactor in core/testenvmanager/dataset/dataset.py introduced new configuration keys (train_index, train_data, train_data_info) and required process_dataset() to use them. Legacy examples (e.g., Cloud-Robotics) still use train_url and test_url in their testenv.yaml configurations. This mismatch caused a NotImplementedError("not one of train_index/train_data/train_data_info") exception.
• Fix Applied: Implemented a backward-compatibility shim within the _parse_config method of core/testenvmanager/dataset/dataset.py. If train_url or test_url is detected and the new keys are unset, the values are automatically mapped to train_index and test_index. This restores full functionality for all legacy examples without requiring repository-wide YAML updates and maintains precedence for new configuration structures.

Which issue(s) this PR fixes:
Fixes #164

[kubeedge-bot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: Fahmid-Arman
To complete the pull request process, please assign jaypume after the PR has been reviewed.
You can assign the PR to them by writing /assign @jaypume in a comment when ready.

The full list of commands accepted by this bot can be found here.

Details

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[gemini-code-assist]

Code Review

This pull request introduces backward compatibility mapping for legacy dataset configurations that use train_url and test_url instead of the newer train_index/train_data/train_data_info fields. However, unconditionally mapping these legacy URLs to train_index and test_index can cause runtime failures if the URLs point to other formats like .jsonl or metadata files. The reviewer suggests inspecting the file format of the legacy URLs and mapping them to the appropriate new fields (train_index, train_data, or train_data_info) accordingly.

Important

The consumer version of Gemini Code Assist on GitHub is being sunset. Starting June 18, 2026, new organization installations will be blocked, and all code review activity will officially cease on July 17, 2026.
For more details on the timeline and next steps, please review the Help Documentation.

[Fahmid-Arman]

Feedback addressed:

• Implemented format-aware routing for legacy train_url and test_url using utils.get_file_format to prevent runtime failures with .jsonl and metadata files.

/assign @jaypume