docs: recommend node/default conditions to avoid dual package hazard

[ShahabAhmed01]

Fixes #52174

Problem

The current documentation suggests using require/import conditions for dual CommonJS/ESM packages, which can lead to the dual package hazard where Node.js might load both versions of the package.

Solution

Add documentation recommending node/default conditions instead:

• node: loads the CJS version in Node.js
• default: loads the ESM version for other platforms (browsers, bundlers)

This approach avoids the dual package hazard while still providing ESM for browsers.

Changes

• Added "Dual CommonJS/ES module packages" section with dual package hazard explanation
• Recommended using node/default conditions with example
• Referenced @babel/runtime as a real-world example

Testing

Documentation-only change, no code changes required.

[nodejs-github-bot]

Review requested:

• @nodejs/loaders