Make besu-evmtool docker images properly multi-arch

[garyschulte]

Description

currently besu CI publishes besu-evmtool docker images for both arm64 and amd64. However, the images are not multi-arch, and the two image types overwrite each other. Whichever arch was the last one pushed for the tag is the one that ends up being published.

Acceptance Criteria

• make besu-evmtool docker images multi-arch for amd64 and arm64, similar to the besu docker images

Steps to Reproduce (Bug)

1. observe the docker image arch types for besu-evmtool, note that there is no rhyme or reason to whether they are arm64 or amd64 images

Expected behavior: [What you expect to happen]
multi-arch images that work for arm64 or amd64