Tell me who has or where can I download drivers for Realtek network cards for the latest versions of hypervisors 7 and higher? Necessary for integration into an ISO image, and further installation on a PC
The drivers for all supported hardware is already present in the ESXi ISO. You may find a couple of unsupported drivers in the VMware Fling site, but those shouldn't be run in production. Check to make sure your hardware is on the HCL, if it is, then the drivers are already present. If it isn't, then probably shouldn't be running it to be honest, least not in a production environment.
Realtek used vmklinux drivers that have been deprecated starting vSphere 7 so you will not be able to get them as they are VMware proprietary and they come embedded into their ISO. However, you could try to use the following USB Network Driver Fling: https://flings.vmware.com/usb-network-native-driver-for-esxi