UefiPayloadPkg: Backward support with python 3.6

UefiPayloadPkg: Backward support with python 3.6

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3960

Currently, UniversalPayloadBuild.py don't have support
python3.6, we use python3.6 will encounter f"" failure
use the change to fix it to support python3.6/3.7/3.8.

Cc: Guo Dong <guo.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>
Cc: James Lu <james.lu@intel.com>
Reviewed-by: Gua Guo <gua.guo@intel.com>
Signed-off-by: KasimX Liu <kasimx.liu@intel.com>