fix: validate githubId parameter in user github-accounts DELETE handler

[tmdeveloper007]

fix: validate githubId parameter in user github-accounts DELETE handler

[vercel]

@TESTPERSONAL is attempting to deploy a commit to the PRIYANSHU DOSHI's projects Team on Vercel.

A member of the Team first needs to authorize it.

[github-actions]

GSSoC Label Checklist 🏷️

@Priyanshu-byte-coder — please apply the appropriate labels before merging:

Difficulty (pick one):

• level:beginner — 20 pts
• level:intermediate — 35 pts
• level:advanced — 55 pts
• level:critical — 80 pts

Quality (optional):

• quality:clean — ×1.2 multiplier
• quality:exceptional — ×1.5 multiplier

Validation (required to score):

• gssoc:approved — counts for points
• gssoc:invalid / gssoc:spam / gssoc:ai-slop — does not score

Type labels (type:*) are auto-detected from files and title. Review and adjust if needed.
Points formula: (difficulty × quality_multiplier) + type_bonus

[vercel]

Deployment failed with the following error:

The provided GitHub repository does not contain the requested branch or commit reference. Please ensure the repository is not empty.

[Priyanshu-byte-coder]

Conflicts arose after recent merges to main. Please rebase on main and resolve conflicts.