Add ARM support for GitHub actions

https://docs.github.com/en/actions/writing-workflows/choosing-what-your-workflow-does/accessing-contextual-information-about-workflow-runs#runner-context

We should add arm support to our github actions.

here's one comment about it:

FYI, I did start looking at this:

1. adding the appropriate `build` to the `matrix` and setting `cross: true` works perfectly!
2. …but then the Python tests fail for that step only.
3. it looks like `actions-rs/toolchain` is [now deprecated](https://github.com/actions-rs/toolchain/issues/216) and equally, it's not clear what the de facto standard Action might be.

So the build isn't too tricky but getting it working in a pipeline is proving a little more rabbit-hole-y than expected.

_Originally posted by @PsypherPunk in https://github.com/RustScan/RustScan/issues/579#issuecomment-2107504881_