fix(void): carry python3-pysocks and constrain the audio and SOCKS floors

Void's stock python3-PyAudio (0.2.12_5) and python3-pysocks (1.7.0_8) sit
below the project floors (pyaudio>=0.2.13, PySocks>=1.7.1). voculinux
depended on both by bare name, which an installed stock package already
satisfies, so a user who had the stock packages was never upgraded.

- add packaging/void/srcpkgs/python3-pysocks: PySocks 1.7.1 from the PyPI
  sdist that uv.lock pins (sha256 3f8804571ebe159c380ac6de37643bb4685970655d3bba243530d6558b799aa0)
- voculinux depends on python3-PyAudio>=0.2.14_1 and python3-pysocks>=1.7.1_1
- the install smoke installs the stock packages first, then voculinux, and
  fails unless each reads back as its carried pkgver
- tests: each constraint must name its carried template's current version
  and revision; the stock version must sit below the floor; the depends
  parser refuses malformed tokens instead of stripping them
- docs: "Version floors" in packaging/void/README.md; a pointer in
  docs/RELEASE_PROCESS.md

Refs #16

tests/test_void_pywhispercpp_template.py

@@ -1,6 +1,6 @@
 """Offline policy tests for the Void template of the whisper.cpp binding (#26).
 
-Spec #16 packages three templates in void-packages layout under
+Spec #16 packages four carried templates in void-packages layout under
 ``packaging/void``; this ticket owns the hard one, ``python3-pywhispercpp``,
 built from the pinned PyPI source distribution with the Vulkan backend,
 shared libraries, and portable CPU flags. Ticket #28 builds the container