python cache key should include python arch

[jeremyd2019]

Currently the actions/cache action is

msys2-autobuild/.github/workflows/build.yml

Lines 89 to 94 in de1083d

	- uses: actions/cache@v2
	with:
	path: ~\AppData\Local\pip\Cache
	key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}
	restore-keys: |
	${{ runner.os }}-pip-

If actions/runner#1185 were implemented, I would change this to ${{ runner.os }}-${{ runner.arch }}-pip-. I don't know that it's worth adding yet another startsWith(matrix.name, 'clangarm') for it though, because the self-hosted runner already still has the pip cache (and in fact the per-user python modules) between runs.

[lazka]

we could just add matrix.name

[jeremyd2019]

true, but then all the runners on x64 couldn't share the cache.

[lazka]

I'm wondering, is there a problem with x64/aarch64 sharing the cache? The wheels should all contain their arch in the filename, and the slight duplication shouldn't hurt much..

[jeremyd2019]

Doesn't hurt much, no, just downloads wheels it won't use, and then downloads the ones it does want.