New packaging script

[ahoarau]

Hi,
Following up on the discussion on #1362 , here's the new packaging script to create a "apt"-like structure.
It rewritten from scratch, but reuses the logic of amalgamate.py.

I took the liberty to:

• Include the COPYING file inside the archive
• Use zip as default output (configurable). Zip is the fastest to uncompress on CMake fetchcontent.
• Include the CMakeLists.txt from the repo so we can fetchcontent just like the whole repo.
• remove the intermediate versionned folder inside the archive. It only contains simde/

to run (use python or uv):

uv run package_simde.py --output simde-1.2.3.zip

This will give:

uv run .\package_simde.py --output simde-1.2.3.zip
Source directory: D:\a\simde\simde
Archive format: zip
Final output path: D:\a\simde\simde-1.2.3.zip
Temporary build directory: D:\a\simde\simde-1.2.3
Creating directory structure: D:\a\simde\simde-1.2.3\simde
Git Hash: 6ca7194220b965e128232f06809a1913e12f0a13
Amalgamating 23 headers from 'D:\a\simde\simde'...
Processing: arm\neon.h
Processing: arm\sve.h
Processing: mips\msa.h
Processing: wasm\relaxed-simd.h
Processing: wasm\simd128.h
Processing: x86\aes.h
Processing: x86\avx.h
Processing: x86\avx2.h
Processing: x86\avx512.h
Processing: x86\bmi.h
Processing: x86\clmul.h
Processing: x86\f16c.h
Processing: x86\fma.h
Processing: x86\gfni.h
Processing: x86\mmx.h
Processing: x86\sse.h
Processing: x86\sse2.h
Processing: x86\sse3.h
Processing: x86\sse4.1.h
Processing: x86\sse4.2.h
Processing: x86\ssse3.h
Processing: x86\svml.h
Processing: x86\xop.h
Copying COPYING file
Copying CMakeLists.txt file
Creating archive D:\a\simde\simde-1.2.3.zip...
Successfully created D:\a\simde\simde-1.2.3.zip

There are some options/securities to change dirs, overwriting etc. just use "-h" for help:

@mr-c No pressure to merge anything. I'd be glad to hear your feedback on this.

[ahoarau]

Also, with a simple ci script we can push the archive automatically on every pushed tag for example:
release.yml

name: Release

on:
  push:
    tags:
      - 'v*'
      - '*'

jobs:
  package-and-release:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v6

      - name: Package simde
        run: python3 package_simde.py --output simde-${{ github.ref_name }}.zip

      - name: Release
        uses: softprops/action-gh-release@v2
        with:
          files: simde-${{ github.ref_name }}.zip