Feature: Add `riscv64` Architecture Support for Docker Image

[rodneyosodo]

Is your feature request related to a problem? Please describe.

Currently, the official supermq image, for example, supermq/auth Docker image, on Docker, does not include support for the riscv64 architecture. This limits the ability to run SuperMQ on newer RISC-V platforms and development boards that are increasingly being adopted in edge and research environments.

SuperMQ image

Redis Image

Describe the feature you are requesting, as well as the possible use case(s) for it.

• Add riscv64 as a target platform in the build pipeline (e.g., using docker buildx multi-arch builds).
• Validate build compatibility with the Go toolchain and dependencies.
• Optionally, provide experimental images until CI/CD runners with riscv64 become stable.

Indicate the importance of this feature to you.

Nice-to-have

Anything else?

If local builds are attempted via GOARCH=riscv64, compilation succeeds.