MLECO-5519: Updating Python packages

Updating the requirements.txt file to fetch later versions of Python
packages. Also, the default build script was still using Arm MPS3
targets for latest NPU. Minor update to this script to pick Arm MPS4
based target instead.

Change-Id: I3815188a81ae34ffbc85acdfb80b97c9b96cdb42
Signed-off-by: Kshitij Sisodia <kshitij.sisodia@arm.com>