refactor: minor changes follows #1348 - #1365

Pull Request Overview

This PR refactors the caching logic in the main setup-node workflow to improve performance and properly guard cache functionality. The changes ensure package cache is only enabled when the cache feature is available and avoid unnecessary package.json reads when the cache field is explicitly specified.

• Only enable package manager caching when the cache feature is available by wrapping logic with isCacheFeatureAvailable()
• Defer reading package.json until needed by moving getNameFromPackageManagerField() call inside conditional blocks
• Restructure cache logic to prioritize explicit cache input over automatic package manager detection

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