setup: qsv python compatibility

[Notgnoshi]

I find the qsv py map mode to be quite useful. But

• The prebuilt binaries for the latest versions no longer include the Python feature
• You need to pick a version built against your system Python version

nots@pandemonium ~/Downloads/qsv $ ./qsvpy310
./qsvpy310: error while loading shared libraries: libpython3.10.so.1.0: cannot open shared object file: No such file or directory
nots@pandemonium ~/Downloads/qsv $ ./qsvpy312 -v
qsv 0.136.0-mimalloc-apply;fetch;foreach;geocode;Luau 0.640;prompt;python-3.12.7 (main, Oct  1 2024, 00:00:00) [GCC 14.2.1 20240912 (Red Hat 14.2.1-3)];to;polars-0.43.1-ee9bafb;self_update-32-32;48.32 GiB-7.99 GiB-49.28 GiB-60.40 GiB (x86_64-unknown-linux-gnu compiled with Rust 1.81) prebuilt

Relates to #146.