Catch2 v3.16.1 amalgamated build
Source: https://github.com/catchorg/Catch2/tree/v3.16.1/extras
Commit: 08092139210881f01a34e60c5f2fd6afa0ea4024

To update, replace catch_amalgamated.hpp/.cpp with the files from the
extras/ directory of the desired Catch2 release tag.
