libpng: Update to 1.6.45

[lazka]

And try dropping the apng patches

* Arch dropped them long ago
* Gentoo is working on it

(see the removed comment for links)

[lazka]

This would affect python-imagecodecs (removed apng support). @kmilos any thoughts/objections?

[kmilos]

We'll just have to patch out support for it in imagecodecs then, and ask upstream to disable it in the future.

[lazka]

Oh, I thought it's optional already there, since not every distro has it. Let me try.

[kmilos]

Just needs del EXTENSIONS['apng'] in customize_build_mingw() of setup.py...

@cgohlke Can we please disable this for MinGW in future versions?

[cgohlke]

Can we please disable this for MinGW in future versions?

Sure, your loss.

[lazka]

So, turns out the apng patches were released in a timely fashion this time around, so might as well continue using them for now.

I'll keep the comments here in mind for future updates, thanks everyone.

[kmilos]

@cgohlke Please disregard the request for now, and apologies for the noise. We should probably switch to managing the features locally via imagecodecs_distributor_setup...