[Bug 51918] wine-gecko 2.47.2 fails to build on host systems with python 3.10

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=51918

--- Comment #2 from Rafał Mużyło  ---
...unless you're referring to that get_default_scheme change, my very
underdeveloped python skills tell me it's pretty obvious: sys.version[:3] ->
sys.version[:4] is to prevent '3.10' becoming '3.1'.

Yes, that would break with older pythons, but fixing it in a compatible way
(like by using sys.version_info) would make the code more complicated. So, you
know, tradeoffs.