chore (main): vendor in Python packaging for Py3.12

[cclauss]

Fixes #211
Fixes #213

Related to:

• Python tests broken #211
• nodejs-windows: python -m pip install packaging #213
• misc: Add Python v3.12 to the testing node-gyp#2862
• distutils is removed in Python 3.12 node-gyp#2869
• Replace uses of python distutils library node-gyp#2888
• Warn about Python v3.12 not working on windows node-gyp#2912
• Python 3.11.6 Missing distutils module node-gyp#2915

distutils was removed in Python 3.12 and the Python Packaging Authority recommends using packaging instead.

Let's vendor in packaging so that installing node-gyp does not require running pip install packaging.

@rzhao271 @DeeDeeG @StefanStojanovic @brjsp

[rzhao271]

Do we still need line 15 in the TOML file?
The line that says dependencies = ["packaging>=23.1"]

[DeeDeeG]

I think for open source license compliance, LICENSE, LICENSE.APACHE and LICENSE.BSD from here: https://github.com/pypa/packaging should be included alongside all the vendored packaging files.

[cclauss]

• dependencies = ["packaging>=23.1"] commented out with an added explanation.
• LICENSE, LICENSE.APACHE, and LICENSE.BSD copied into pylib/packaging

[targos]

rubberstamp

[DeeDeeG]

This PR worked for me!

The details of my testing are posted below, for anyone who is curious.

Test method:

• This post is about testing in Ubuntu (Docker ubuntu:latest image), since the Python package from Ubuntu package repos doesn't provide setuptools/distutils, unlike Python from HomeBrew on mac, which seems to come with several packages by default, sometimes including setuptools that provides distutils, or packaging... Wasn't totally sure about this, so I tested on Ubuntu which I know doesn't come with any of these "out of the box".
  • I initially tried testing in macOS, but gyp-next v0.15.1 already works with my copy of Python 3.12 from Homebrew. Homebrew's Python 3.12 appears to come with packaging "out of the box"...
• Install needed packages (apt-get update && apt-get install add-apt-repository software-properties-common git curl make gcc g++ python3 pkg-config libsecret-1-dev)
• I installed python3.12 from deadsnakes PPA (add-apt-repository ppa:deadsnakes/ppa and apt-get install python3.12)
• Using nvm, I installed NodeJS v18.18.2, which comes with with npm v9.8.1
• I cloned node-keytar repo, as a random repo that I know has native C/C++ code to build in it, and ran npm install in it.
• In my local checkout of node-gyp repo, I did ./update-gyp.py v0.16.0 to sync gyp-next with this fix in it.
• I did export PYTHON=python3.12 to make sure to use Python 3.12 with node-gyp in the following tests
• Then I tried ~/node-gyp/bin/node-gyp.js rebuild in the node-keytar repo I cloned before

Confirming this fix was needed (Testing the "null hypothesis"):
I also wanted to confirm once again that this fix is needed and my testing setup is sound, so I checked a couple of other things.

• node-gyp main branch (no modifications) has an error ModuleNotFoundError: No module named 'distutils' ❌
• node-gyp main branch + gyp-next v0.15.1 has an error ModuleNotFoundError: No module named 'packaging' ❌

Main Result (This PR Fixes the Errors):

• node-gyp main + gyp-next v0.16.0 (including this PR) works for me on Python 3.12 ✅

[cclauss]

I confirm that macOS homebrew's brew install python@3.12 will also install python-packaging.
You can do brew list to verify its presence.