Updated Linux and macOS wheels matrix variable name

[radarhere]

Minor suggestion.

Renames archs in Linux and macOS

Pillow/.github/workflows/wheels.yml

Lines 33 to 46 in 27eacdd

	build:
	name: ${{ matrix.name }}
	runs-on: ${{ matrix.os }}
	strategy:
	fail-fast: false
	matrix:
	include:
	- name: "macOS x86_64"
	os: macos-latest
	archs: x86_64
	macosx_deployment_target: "10.10"
	- name: "macOS arm64"
	os: macos-latest
	archs: arm64

to cibw_arch, to better match the variable name used in Windows

Pillow/.github/workflows/wheels.yml

Lines 83 to 93 in 27eacdd

	windows:
	name: Windows ${{ matrix.arch }}
	runs-on: windows-latest
	strategy:
	fail-fast: false
	matrix:
	include:
	- arch: x86
	cibw_arch: x86
	- arch: x64
	cibw_arch: AMD64

[hugovk]

@nulano What do you think about removing matrix.arch from the Windows job so it only has matrix.cibw_arch, and refactoring build_prepare.py to use matrix.cibw_arch values?

More effort than it's worth, or a nice cleanup?

[nulano]

I have considered it. It would make sense, but I didn't feel like doing it 😄.
The current arch definition matches the use by webp, so a new key would need to be added to ARCHITECTURES.
...is what I was going to write, but looking at it now, webp in fact uses a different value for arm.
It might also make sense to build webp with CMake (which doesn't need the arch at all) instead of NMake; I'll take a look.

Edit: #7693