Closes #19709 (comment)
Closes #24194 (comment)

This PR fixes case where if eslint cached install is partial or stale, Zed can try to launch a missing eslintServer.js and the server crashes with MODULE_NOT_FOUND.

Error: Cannot find module '/Users/.../languages/eslint/vscode-eslint-2.4.4/vscode-eslint/server/out/eslintServer.js'

Self-Review Checklist:

• I've reviewed my own diff for quality, security, and reliability
• Unsafe blocks (if any) have justifying comments
• The content is consistent with the UI/UX checklist
• Tests cover the new/changed behavior
• Performance impact has been considered and is acceptable

Release Notes:

• Fixed ESLint server startup failures caused by reusing an incomplete or stale cached server install.