Issue title: Wheel support for linux aarch64
 Issue body: Reopen: https://github.com/fastavro/fastavro/issues/479

The last time `aarch64` was present in the release 1.4.12, but from the 1.15.0 is not present.

Could you return it back?

Thanks! 
 Comments: 
 Comment 0: Currently the aarch64 builds are done via Travis because it doesn't seem to be supported on Github Actions. Unfortunately, those builds don't always work because of some unknown issues on the Travis platform. The builds will just hang and not complete and if I restart them they will hang at a different point in the build.

All this to say, if you know of a way to build aarch64 wheels more consistently I will try that because Travis isn't very reliable.

Since they aren't reliable currently I try to include them when Travis cooperates but if it is acting up then unfortunately they don't get included.
 Comment 1: Have you considered this one? 

https://github.com/marketplace/actions/run-on-architecture

Maybe I could try it and raise PR if it works.
 Comment 2: or we could take the approach from `psutil` library, it is not merged yet, but they have an open PR for that:
https://github.com/giampaolo/psutil/pull/2103
 Comment 3: I like the second option and I think it is working. Still doing a little tweaking, but hopefully there should be aarch64 wheels in the next release
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