Fails in Web Worker Environment due to Worker-Timers Dependency

[hibrandonevans]

Issue Description:

I've encountered a bug when using mqtt.js version 5.3.2 in a Web Worker environment. The issue arises due to the worker-timers library dependency utilized in this version of mqtt.js.

Problem Details:

The worker-timers library makes use of the new Worker API, which is not available in the Web Worker environment. As a result, attempting to use mqtt.js 5.3.2 within a Web Worker leads to a failure, with an error indicating the absence of the new Worker API in this context.

[robertsLando]

Arggg... I'm sorry for that but there is actually no test coverage for workers, I definitely should add one when I have some time and once I found put how! Let me fix this asap 🙏🏻