I think to uninstall would be something like the following:
$ sudo dkms remove -m rtl8821ce -v ??? -k 5.13.12-200.fc34.x86_64
I don’t know what the version number is for the module you currently have installed. So I just put question marks (?) in that field. You should be able to run dkms status to see a list of what is currently installed (including the version numbers for the module and kernel).
To load the kernel-provided driver should just be a matter of running modprobe rtw88_8821ce. Use lsmod to see a list of what drivers are currently loaded. Any errors should be logged in the output of dmesg.
Edit: There should be a script to permanently remove the dkms module from your installation. The dkms module is probably installed under /usr/src/rtw88_8821ce-??? and I think you could just delete that directory if necessary (after you have removed the module from the kernel).