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

Using the technique described in #560 and implemented in #561
The same can be done for mqttbroker

Many of the examples/ repos have Dockerfile.amd64 / Dockerfile.arm / Dockerfile.arm64 / Dockerfile.ppc64le
I did a meld on some of these Dockerfiles and they are slightly different. (which is not good)
These multiple Dockerfiles and differences are unnecessary. We could delete them all. Create one common Dockerfile

Then in the Makefile, tell the docker build --platform linux/$(ARCH)
Docker/Podman will figure out which arch image to pull and build.

Describe the solution you'd like.

Remove all the Dockerfile.* files. Create a common Dockerfile