The README.md in the git repository for LimeSuite points you to instructions on how to either install the binaries (These are for Debian amd64/arm64/armhf based OS’es only) or how to install from source.
Raspbian is based on Debian, so you have two options compile everything from source code the right way (mostly shown in the instructions). Or run the current 32-bit binaries on your 64-bit OS which you needed to run for access to all 8GiB of your RAM.
e.g. (I don’t own a RPi4, so this is me guessing at the commands that you will need to run).
$ sudo dpkg --add-architecture armhf
$ sudo add-apt-repository -y ppa:myriadrf/drivers
$ sudo apt update
$ sudo apt install limesuite:armhf liblimesuite-dev:armhf limesuite-udev:armhf limesuite-images:armhf
$ sudo apt install soapysdr-tools:armhf soapysdr-module-lms7:armhf
And you will probably need to add the device rule by hand.