fix(file_format): cover jsonl in addition to json for taskset definitions

[s7manth]

• tasksets can be exported in jsonl format too, in addition to json format

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Note

Low Risk
One-line glob change in Harbor export cleanup only; no auth, runtime, or grading behavior changes.

Overview
Harbor export copies the env build context into each task’s environment/ folder and already removes copied HUD taskset definition files so they don’t end up in the image.

The cleanup glob is widened from *.json to *.json*, so .jsonl taskset exports (and other json-prefixed names) are removed the same way as plain .json files when the source tasks file lives in that build context.

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