fix: querySets are not deleted with consecutive withPerformanceCallback calls

Scenario 1:

const pipeline = ... createPipeline();

//...

const draw = () => {
  pipeline.withPerformanceCallback(...).draw(...);
}

We never delete existing querySets. This causes errors, because eventually, the browser cannot allocate any new querySet.

Scenario 2:

const pipeline = ... createPipeline().withPerformanceCallback(...);

//...

const draw = () => {
  pipeline.withPerformanceCallback(...).draw(...);
}

This doesn't cause any trouble, because we allocate a single querySet and reuse it.

Start from the withPerformanceCallback implementation and trace how querySets are allocated in the two scenarios described. Reproduce consecutive callback calls in a WebGPU environment, then verify that replaced querySets are deleted and repeated draws no longer exhaust browser querySet allocation.