Feat: PR Assignment Validation & Spam Prevention

[aniket866]

Describe the feature

Open repositories often receive pull requests linked to issues that are not assigned to the contributor. This leads to:

• Duplicate or conflicting work

• Low-quality / drive-by PRs

• Increased maintainer review burden

• PR spam during hackathons or open calls

Why?

After this PR raised which is not yet assigned will be automatically labelled as not-assigned

Add ScreenShots

N/A

Record

• I agree to follow this project's Code of Conduct
• I want to work on this issue

[github-actions]

👋 Thanks for opening this issue! The maintainers will review it shortly. Till then, do not open any PR. This is a strict rule we like to follow around here :)

[SakshiGupta26]

Hi, this feature sounds interesting. I would like to work on it once maintainers approve and open it for contributions.