provide an opt-out of raw-dylib

[davidhewitt]

This is my attempt to fix #6157

Where this differs from #6164 and #6182:

• I don't try to extend raw-dylib linking to mingw for now, instead I make PyO3 fall back to requiring the full import lib.
• I don't try to add "lib" prefix, unlike internal: [codex] try fix mingw libname #6164 (this is done automatically by the gnu linker)
• Both PRs claim that mixed C/Rust projects might need the full import library; rather than guess at when this should happen I introduce PYO3_USE_RAW_DYLIB=0 opt-out.

I verified this by hand on a windows box in a mingw environment; it seems to work correctly where main is broken.

[davidhewitt]

cc @chirizxc - I think by introducing a fallback to using the import lib (i.e. the "old" behaviour) this might be a better route to go down compared to #6164? Thanks for that PR and sorry I was so slow to get deep into it.

[messense]

Providing a opt-out sounds good to me. Note that I did also verify a revision of #6182 on github actions in https://github.com/messense/pyo3/actions/runs/28695802239

[chirizxc]

cc @chirizxc - I think by introducing a fallback to using the import lib (i.e. the "old" behaviour) this might be a better route to go down compared to #6164? Thanks for that PR and sorry I was so slow to get deep into it.

I'm fine with any option (since I don't use these platforms)

@ognevny what do you think about this?

[ognevny]

lgtm

[davidhewitt]

Thanks all, I think I will proceed to merge this and ship 0.29.1. (Probably will get it live tomorrow.)

[chirizxc]

- // "lib" prefix is not automatically added).)
+ // "lib" prefix is not automatically added)