feat(cdp): update node version in ci

[MarconLP]

Important

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Problem

Corepack is broken with 18.12.1

Let's see if we can easily upgrade the version?

Changes

Did you write or update any docs for this change?

• I've added or updated the docs
• I've reached out for help from the docs team
• No docs needed for this change

How did you test this code?

[greptile-apps]

PR Summary

Updates Node.js version from 18.12.1 to v18.20.6 across all CI workflow files to fix broken Corepack functionality while maintaining backward compatibility.

• Consistently updates Node.js version in all CI workflow files including .nvmrc, .github/workflows/ci-e2e-playwright.yml, ci-frontend.yml, ci-plugin-server.yml, and others
• Adds 'v' prefix to version numbers for better alignment with Node.js version conventions
• Maintains version consistency within Node.js 18.x LTS branch for backward compatibility
• Fixes specific Corepack functionality issues present in version 18.12.1

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[github-actions]

Size Change: 0 B

Total Size: 3.74 MB

ℹ️ View Unchanged

Filename	Size
frontend/dist/toolbar.js	3.74 MB

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