build: make rule to generate standalone python zipapp application

[R1kaB3rN]

Supersedes #149 and closes #148

Fixes user installs by installing umu-launcher as a reproducible zipapp at $HOME/.local/bin.

Additionally, this feature gives clients another installation option and will come with the advantage of simplifying updates, simplifying client logic, and reducing the likelihood of data corruption.

[R1kaB3rN]

cc @loathingKernel

A review would be appreciated

[loathingKernel]

I am attaching a patch with the suggested changes to avoid any ambiguities stemming from my review comments. It's just a basis, we can adapt it along with the discussion.

zipapp-makefile.patch.txt

[loathingKernel]

Side note: the makefile has collected some clutter, maybe we should take this opportunity to clean it up a bit too.

[loathingKernel]

Looking at the action's log, it is odd that creating a virtualenv results in a permission error, I don't understand why that happens either.

[R1kaB3rN]

Tested on latest stable versions of Lutris (0.5.17) and Heroic (2.15.1) to ensure this change doesn't break them by simply replacing the umu directory contents.

Note: For clients who choose to subscribe to zipapps, it will require updating their logic to call umu-run in their runtime directory. Otherwise, they'll need to ensure all dependencies are included within the umu directory where the parent directory contains the name runtime. In the case for Heroic, the following files need to be in $HOME/.config/heroic/tools/runtimes/umu:

current_version            __main__.py                 umu_consts.py                 umu_proton.py   umu_version.json
filelock                   python_xlib-0.33.dist-info  umu_launcher-0.1.0.dist-info  umu_run.py      Xlib
filelock-3.15.4.dist-info  six-1.16.0.dist-info        umu_log.py                    umu_runtime.py
__init__.py                six.py                      umu_plugins.py                umu_util.py