Translation sync failed for PR #1050 (zh-cn)

### Translation sync failure

**Source PR**: #1050
**Target repo**: QuantEcon/lecture-python.zh-cn
**Target language**: zh-cn

### Errors

- PR creation failed: Invalid request.

"sha" wasn't supplied. - https://docs.github.com/rest/repos/contents#create-or-update-file-contents

### Recovery

Once the issue is resolved, comment `\translate-resync` on PR #1050 to retry.