Fix incompatibility with CMake 4

cxxopts 2 is incompatible with CMake 4 so upgrade to 3.2.1

The latest version of doctest is still incompatible with CMake 4 so
patch the sources to make it compatible.
The patch command used is not pretty but it's pure CMake so doesn't rely
on any other tools being installed.

Signed-off-by: Michael Platings <michael.platings@arm.com>
Change-Id: I563d93004f73ef0e1cf7de740e7159c4aeaea1dc