Link against libgfortran statically when static feature is enabled

[emmatyping]

I use openblas for a Python package, so I statically link most of the C dependencies I have. However, when I activate the static feature it failed the manylinux check because it is dynamically linking to libgfortran.so.5

This seems to happen when the lapacke feature is activated, but not otherwise.

[IvanUkhov]

If you need OpenBLAS for a Python package, how does Rust appear in the picture?

[emmatyping]

I'm using ndarray and rust-numpy , and lapack routines, bound back to Python via PyO3 and rust-numpy