Include keypoints_metadata.json when uploading model

[grzegorz-roboflow]

What does this PR do?

Include keypoints_metadata.json when uploading model, so users can upload keypoint models

Type of Change

• Bug fix (non-breaking change that fixes an issue)

Testing

Tested locally

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code where necessary, particularly in hard-to-understand areas
• My changes generate no new warnings or errors
• I have updated the documentation accordingly (if applicable)

Additional Context

N/A

[tonylampada]

LGTM

there's improvement suggestion from 🤖 review that might be worth looking into:

a user deploying a pose model from a directory that lacks keypoints_metadata.json gets a successful upload acknowledgment but a broken deployed model — with no feedback about what went wrong.

This is a "should fix before merge" concern, not a blocker, because the PR already improves the status quo