Add GSSoC Label and Level for Auto labels assignment

[dimpal-yadav]

Which issue does this PR close?

• Closes Add GSSoC Label and Level for Auto labels assignment #76

Rationale for this change

This PR adds an automatic label assignment workflow for all newly created issues and pull requests.
It ensures:

• Labels Level 1 / Beginner, Level 2 / Intermediate, Level 3 / Advanced and GSSoC 25 are automatically created (if not already present) with proper colors.
• Labels are assigned based on title and body keywords to indicate complexity/impact.
• Works for both issues and PRs, simplifying contribution management.

This improves consistency, saves manual labeling effort, and helps track GSSoC contributions automatically.

What changes are included in this PR?

• Added a new GitHub Actions workflow file:
  .github/workflows/auto-label.yml
• Logic to:
  • Create missing labels with predefined colors
  • Assign labels automatically to new issues and PRs
  • Determine complexity level (1/2/3) from title/body keywords
  • Always assign GSSoC 25 label

Are these changes tested?

• Workflow tested by creating dummy issues and PRs in a separate branch to ensure labels are automatically applied.
• Verified that existing labels are not duplicated and colors match the defined scheme.

Are there any user-facing changes?

• No direct user-facing changes.
• Contributors will see labels applied automatically when they open an issue or PR.