fix: platform tag for GraalPy

[mayeut]

When running a 64-bit version of GraalPy (either x86_64 or aarch64), packaging returns the wrong platform tag (either i686 or armv8l).

Fix this by using the same default implementation as found in stdlib platform.architecture https://github.com/python/cpython/blob/4d4393139fae39db26dead33529b6ae0bafbfc58/Lib/platform.py#L713-L716

fixes #710

cc @timfel

[mayeut]

IMHO, the whole discussion around macOS in #614 was out of scope. This does not change a thing for macOS compared to the previous implementation.
If there was an issue with the previous implementation on macOS, then there should be an issue opened for that.

There are no tests for _32_BIT_INTERPRETER, should we try to add some ? based on what ? (I'm thinking observed values of sys.maxsize and struct.calcsize("P") for now)

[brettcannon]

There are no tests for _32_BIT_INTERPRETER, should we try to add some ?

Definitely, if we can figure out a good way to. 😅

based on what ? (I'm thinking observed values of sys.maxsize and struct.calcsize("P") for now)

It's definitely better than nothing. You can also monkeypatch the struct module if we end up going with your PR.

[mayeut]

I added some tests for _32_BIT_INTERPRETER
They were checked with observations from https://github.com/mayeut/sandbox/actions/runs/5984106625

[brettcannon]

Thanks!