Support multiple different CPU architectures

[ewels]

BioConda is now generating builds for linux/arm64 CPU architectures. With the move to Seqera Containers (#5832) this means that we can now offer out-of-the-box support for both linux/arch64 and linux/arm64.

Basically everything should be taken care of here as part of #5832 - however it's possible that some BioConda packages will not have yet been built for ARM64, so leaving this issue partly as a placeholder for that.