Migrate to Cython3

[ZipFile]

As title says. Major incompatibility with v0.29 was new mandatory dunder mangling, so solution was simply to rename them. Otherwise migration was pretty much straightforward.

Notes:

• Cython 3 no longer recommends commiting C files. I already have some drafts, will submit PR after this one is merged.
• So far it builds and runs on CPython 3.7-3.12 (with coverage).
• On PyPy it won't build with DEPENDENCY_INJECTOR_DEBUG_MODE (probably Cython issue), without debug mode looks like it builds and runs fine (no coverage ofc), but there are few failing tests, need investigate more if this is related to version of PyPy itself (I was testing with 7.3.16).
• Not exactly sure about segfaults mentioned in Roadmap 2024 #812, but majority of tests were failing because Cython 3 started mangling attributes that were previously unmangled.

[rmk135]

@ZipFile wow, thanks for the PR!

[coveralls]

coverage: 91.623%. remained the same
when pulling cb81e56 on ZipFile:cython3
into 2c998b8 on ets-labs:master.

[ZipFile]

Looks like tox was ignoring DEPENDENCY_INJECTOR_DEBUG_MODE env var set from GHA pipeline, coverage supposed to be around 94% with *.pyx included. Pushed fix + extra logging.