Add support for pre-ACCELERATE_NEW_LAPACK Accelerate on iOS.

[freakboy3742]

Accelerate has three flavours:

• Original LP64 (interface=lp64)
• ACCELERATE_NEW_LAPACK LP64 (interface=lp64)
• ACCELERATE_NEW_LAPACK ILP64 (interface=ilp64)

ACCELERATE_NEW_LAPACK is only available from macOS 13.3/iOS 16.4.

This PR enables the use of Accelerate on older iOS releases (back to 13.0), but disables the use of ACCELERATE_NEW_LAPACK on those versions.

[freakboy3742]

One side thought - it would be possible to extend this to allow for pre-NEW_LAPACK Accelerate support on macOS as well, using a similar pattern; however, I don't know if there's any interest in that.

[rgommers]

Not really. Both because that old Accelerate is pretty buggy (see https://github.com/scipy/archive/blob/main/wiki/dropping-accelerate-support.md), and because I don't really want to spend time or increase complexity to deal with building from source on macOS versions that old.

[freakboy3742]

I figured that was likely the case. I just wanted to mention the option since the parallel exists.

[freakboy3742]

@rgommers Just following up on this; is this a change you're comfortable with?

[freakboy3742]

@rgommers Sorry to nag on this one - but any update on whether this can be merged? It's currently the last remaining blocker on iOS support for NumPy.