The IDE does not have functionality to uninstall a library but if you delete the C:\Users...Inc...\Documents\Arduino\libraries\Adafruit_Circuit_Playground folder the library will no longer be available
In case of accidents you might like to move the folder somewhere else initially until you know all is well
Cross-posting is against the Arduino forum rules. The reason is that duplicate posts can waste the time of the people trying to help. Someone might spend a lot of time investigating and writing a detailed answer on one topic, without knowing that someone else already did the same in the other topic.
Repeated cross-posting can result in a suspension from the forum.
In the future, please take some time to pick the forum category that best suits the subject of your question and then only post once to that forum category. This is basic forum etiquette, as explained in the "How to get the best out of this forum" guide. It contains a lot of other useful information. Please read it.