Function untrack

untrack<T = any>(this: void | object, fn: () => T): T
Runs a function without tracking property accesses.

Reads performed inside the callback will not subscribe the current effect to the accessed properties. Useful for breaking cycles or performing intentional non-reactive reads.

The context is determined by this, following the same rules as signal.
Type Parameters
- T = any
  The type of the returned value.
Parameters
- this: void | object
  Reactive context; defaults to the shared global context.
- fn: () => T
  The function to run outside the tracking system.
Returns T
The value returned by fn.
Example
```
const state = signal({ count: 0 });
// reads without subscribing
const dispose = effect(() => {
  untrack(() => {
    console.log(state.count);
  });
});
// triggers the effect
state.count += 1;
// later …
dispose();
```
- Defined in signal.ts:225