Experimental: build a scons-local zipapp (PEP 441)

[mwichmann]

To use, set do_zipapp to True in site_scons/scons_local_package.py (notice as submitted, building is disabled)

Will produce a build/dist/scons-local-${VERSION}.pyz which can be directly executed - copy to a work dir, and run as

python scons-local-4.3.1.pyz`

or even

./scons-local-4.3.1.pyz

Windows should have a file association for .pyz files, otherwise it works there too by calling it as an argument of the interpreter.

site_scons/zip_utils.py doesn't need a fallback for the zip module, it's guaranteed to be in supported Python versions (as is zipapp), so was able to simplify the existing code a bit.

Signed-off-by: Mats Wichmann [email protected]

Contributor Checklist:

• [ ] I have created a new test or updated the unit tests to cover the new/changed functionality.
• [ ] I have updated CHANGES.txt (and read the README.rst)
• [ ] I have updated the appropriate documentation