Bundle unit tests with release tarball

[diizzyy]

For helping with packaging and testing it would be nice if unit tests could be bundled with the static release tarball

[zeux]

Just curious if the GH tarballs are helpful here: historically, pugixml releases have come with two "manually" packaged archives (.tar.gz and .zip) that contain the files necessary to use pugixml: headers/sources, build system integration and documentation. .zip also has Windows line endings. However, in addition, GitHub automatically creates .tar.gz (and .zip) files for each release that have the full repository contents - including unit tests.

E.g.:

• https://github.com/zeux/pugixml/releases/download/v1.16/pugixml-1.16.tar.gz is the "manual" archive
• https://github.com/zeux/pugixml/archive/refs/tags/v1.16.tar.gz is the "automatic" one.

("manual" in quotes because these are created by a Makefile step but that step is ran manually)

[diizzyy]

The main issue is that they're not static but also the filename isn't great if you want to be picky.
https://github.blog/open-source/git/update-on-the-future-stability-of-source-code-archives-and-hashes/