Fix/ci pnpm action setup

[desireddymohithreddy0925]

Summary

Fixes the GitHub Actions CI pipeline failures by reverting the pnpm/action-setup configuration back to the stable version: 9, resolving the self-installer exit code 1 errors caused by the unsupported version 11.

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Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 💥 Breaking change (fix or feature that changes existing behavior)
• 📝 Documentation update
• ♻️ Refactor / code cleanup (no functional change)
• ⚡ Performance improvement
• 🔒 Security fix
• 🧪 Tests only (CI/CD pipeline configuration)

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What Changed

• Updated .github/workflows/automated-tests.yml to use version: 9 for pnpm/action-setup@v6.
• Updated .github/workflows/ci.yml to use version: 9 for pnpm/action-setup@v6.
• Updated .github/workflows/e2e.yml to use version: 9 for pnpm/action-setup@v6.
• Updated .github/workflows/visual-regression.yml to use version: 9 for pnpm/action-setup@v6.

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How to Test

1. Merge this Pull Request into the main branch.
2. Observe that Dependabot PRs (such as PR [GOOD FIRST ISSUE] Add loading skeleton to ContributionGraph #3 / chore(deps): bump actions/github-script from 7 to 9 #3158) will automatically rebase against the updated main.
3. Check the "Checks" tab on any active Pull Request to verify that the pnpm/action-setup step succeeds and the dependencies install correctly without throwing a self-installer exits with code 1 error.

Expected result: All Continuous Integration Security & Audit Suite and Type Check jobs should pass successfully.

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Screenshots / Recordings

N/A - CI/CD pipeline fix

[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