Update macOS UI reference to “System Settings”

[abhiramk6]

made changes to rename system preferences to system settings according to new mac os name change

Docs: Update macOS UI reference to “System Settings”

This PR updates the documentation in docs/server.rst to reflect the latest macOS UI terminology. Specifically, it replaces the outdated term “System Preferences” with “System Settings”, aligning with macOS Ventura and later versions.

What Changed • Line updated in instructions to disable AirPlay Receiver from: • "System Preferences" → "System Settings"

Notes • No issue was created for this change, as it is a minor documentation correction. • This update does not affect any code or behavior. • No test or changelog entry required per contribution guidelines for doc typo-level fixes.