[BUG] mutation observer provides the dom changes incrementally, which can be used instead of doing `querySelectorAll` all the time

[source](https://github.com/nxtcoder17/control-center/blob/56ee04a56239aeb9aac5fd5ec3e7d301a1bf7bd9/src/content-scripts/youtube.com/removes-youtube-shorts.js#L82C1-L85C4)


### reference links
- https://javascript.info/mutation-observer