How do I find out any information on running the SystemReady tests on a bare metal system without a Rich OS

There are two user guides provided by ACS to support this: one for BSA ACS and one for SBSA ACS.  These can be found at  https://github.com/ARM-software/bsa-acs/tree/main/docs and https://github.com/ARM-software/sbsa-acs/tree/master/docs respectively.