Fix k6/timers always being reported as used

[mstoykov]

Brief summary

Due to how #3589 was implemented it is currently reported that every script is using k6/timers even if they do not.

k6 version

v0.51.0

OS

all

Docker version and image (if applicable)

No response

Steps to reproduce the problem

Run a script without using k6/timers

Expected behaviour

It isn't reported it uses k6/timers

Actual behaviour

it is reported k6/timers are used.