Testing on aarch and windows 32 bit

[pnorbert]

openpmd-api is testing on these platforms:

Linux 32bit (i686) - GH actions, cross-compiled
Linux 64bit (x86_64) - GH actions
Linux aarch64 - [CircleCI](https://github.com/openPMD/openPMD-api/blob/dev/.circleci/config.yml)
Linux ppc64le (little endian) - [TravisCI](https://github.com/openPMD/openPMD-api/blob/wheels/.travis.yml) using its free [partner queue](https://docs.travis-ci.com/user/billing-overview/#usage---credits)
Windows 32bit (x86) - [GH actions, cross-compiled](https://github.com/openPMD/openPMD-api/blob/wheels/.github/workflows/build.yml) from 64bit
Windows 64bit (x86_64) - [GH actions](https://github.com/openPMD/openPMD-api/blob/wheels/.github/workflows/build.yml) from 64bit
MacOS 64bit (x86_64) - [GH actions](https://github.com/openPMD/openPMD-api/blob/wheels/.github/workflows/build.yml) from 64bit
MacOS 64bit (aarch64/arm64) - [GH actions, cross-compiled](https://github.com/openPMD/openPMD-api/blob/wheels/.github/workflows/build.yml) from x86_64
GH actions has now official aarch64 hardware, too

See https://github.com/openPMD/openPMD-api/blob/wheels/.github/workflows/build.yml

Can we also test on aarch64/arm64?

[vicentebolea]

#4125