Support multiple platform architectures (e.g. arm32/arm64)

### Proposal

Enable running self hosted gateways on ARM based platforms.

### Use-Case

ARM based platforms are growing in adoption. To be able to run a self hosted gateway on these platforms the image should be build for multiple platform architectures.

### Anything else?

_No response_

Start by locating the gateway image build and release entry points that control target architectures. Determine how arm32 and arm64 images should be produced and published, then verify that the resulting images run on both platforms; the issue is done when ARM-based self-hosted gateways can be deployed from those images.

Written by the indexing model from the issue text.