ci: add Android x86_64

[cakebaker]

This PR enables Android x86_64 in the CI/CD as suggested in #5821 and should be merged after it.

[github-actions]

GNU testsuite comparison:

Skip an intermittent issue tests/tail/inotify-dir-recreate (fails in this run but passes in the 'main' branch)

[sylvestre]

More failure!

[cakebaker]

Unfortunately yes :|

[cre4ture]

Do you have an idea why this android build is so unstable?
The emulator is configured for 2GB (2048MB) of RAM.
Can we test if increasing this to e.g. 8GB helps?
My phone has 12GB of RAM and I had sporadic errors in the build & test due to memory allocation errors.

[cre4ture]

I started to look into the problem of why the android build is instable and how to improve.
I have one question: why is it running on a mac os runner? I read today that mac os the most expensive runner. Windows is next and linux would be the cheapest. So why is the android-runner a mac-runner?

[tertsdiepraam]

I honestly don't know. Maybe you can find some explanation in the PR that introduced the Android CI?

[cakebaker]

I think the original reason was that hardware acceleration was only available on macOS VMs: ReactiveCircus/android-emulator-runner#46 . According to ReactiveCircus/android-emulator-runner#46 (comment) this is no longer relevant and so it might be worth to try to switch to Linux.

[sylvestre]

it was the same with the freebsd runner (running on mac first), it is now much better :)

[sylvestre]

let's take this patch anyway :)