Purpose

This change refactors the resolveAllDNS function to simplify its concurrency handling.

Changes:

• Removed the initial concurrency pattern within resolveAllDNS that used a select loop to interleave sending work (workCh) and receiving results (dnsResponseCh).
• Retained and cleaned up the second pattern (previously using workCh2/dnsResponseCh2, now using the standard workCh/dnsResponseCh names) which follows the simpler and generally more robust "send all work -> close work channel -> receive all results" approach.

Reasoning:

• The original function contained two distinct and somewhat redundant methods for achieving the same goal.
• The retained pattern is easier to understand, less complex to manage, and sufficient for this fan-out/fan-in task.
• This simplification improves the overall readability and maintainability of the function.

No functional changes are expected as a result of this refactoring; it purely streamlines the implementation.

Other small changes

• Rework function comments
• check for no results found