Investigate python3.12 http fs path parsing errors

[ap--]

Two test cases in upath/tests/implementations/test_http.py::test_empty_parts fail across OSes only for python3.12.

See: https://github.com/fsspec/universal_pathlib/pull/232/checks
(and all the other PRs)

Need to investigate...

[ap--]

🕵️ investigating further:

Occurs with 3.12.4
Does not occur with 3.12.2

Can now reproduce locally.

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... root cause seems to be a change in behavior of urllib.parse.SplitResult

# for example python3.9
>>> SplitResult(scheme="", netloc="", path="//", fragment="", query="").geturl()
'//'

# python 3.12.4
>>> SplitResult(scheme="", netloc="", path="//", fragment="", query="").geturl()
'////'

[ap--]

It's related to this PR: python/cpython#113563

It seems that new behavior is intended, and it's being backported to 3.8, 3.9, 3.10, and 3.11.