fix(qqbot): add return_exceptions=True to asyncio.gather in chunked upload

[x7peeps]

Summary

Add return_exceptions=True to the asyncio.gather() call in _run_with_concurrency() (gateway/platforms/qqbot/chunked_upload.py).

Problem

When uploading a file via QQ Bot's chunked upload API, multiple parts are uploaded concurrently via _run_with_concurrency(), which uses asyncio.gather() without return_exceptions=True.

If any single part upload fails (network error, rate limit, transient HTTP error), the unhandled exception propagates through gather(), cancelling all other in-flight part uploads and crashing the entire upload operation.

This is the same class of bug already fixed in other gather calls (feishu #64864, context_references #64726, agent #62902).

Fix

One-line change: add return_exceptions=True to the asyncio.gather() call at line 602, so per-part failures are isolated instead of cascading to all concurrent uploads.

Testing

• Syntax check passed (py_compile)
• Behavior verified

[alt-glitch]

This was generated by AI during triage.

Duplicate of #61302: both make the same one-line asyncio.gather(..., return_exceptions=True) change in QQBot chunked upload handling.

[x7peeps]

Closed as duplicate per maintainer feedback.