sudo apt remove linux-headers-5.15.0-84-generic linux-modules-5.15.0-84-generic linux-modules-extra-5.15.0-84-generic linux-image-5.15.0-84-generic
Next, please read here to set your current working kernel as default. That way it stays that way even is system upgrades add a newer kernel. In this manner, you can boot into and *test a later kernel without worry.