Similarly to the LibCpp parser regression tests, these tests run the
preprocessor on the .cpp test files under
Userland/LibCpp/Tests/preprocessor, and compare the output with existing
.txt ground truth files.
This commit removes the only 3rd party library (and its usages)
in serenity: puff, which is used for deflate decompression. and
replaces it with the existing original serenity implementation
in LibCompress. :^)
The bash version takes around 15 seconds to run; that is way too slow.
This python3 version should take less than one second to run. :^)
Also, the script will now also check .py files and .txt CMake files.
