It would be best to leave them installed. Fedora Linux usually keeps three recent kernels and a rescue image. For more information, see Old Kernels Removal - #7 by ankursinha
Btw, on a non-dual boot system (like yours) grub shouldn’t even show at boot unless you configured it to show up.
Thank you for your answer. I only have one Fedora system, and this interface is only the first reboot after making updates. Just know the method, thank you again.