Refactor packages/queue/ack.js to use parameterized PostgreSQL queries

[keyurparashtekar]

While reviewing the queue package, I noticed that packages/queue/publish.js
already uses parameterized PostgreSQL queries ($1, $2), but
packages/queue/ack.js still constructs SQL using string interpolation.

Refactoring ack.js to use parameterized queries would:

• align it with the existing pattern used elsewhere in the package,
• avoid manual SQL construction,
• improve readability and maintainability,
• follow PostgreSQL query parameterization best practices.

I'd be happy to work on this if the maintainers think it's a useful improvement.