Fabric no longer publishes its own CouchDB Docker image. Instead, just use the official CouchDB Docker image, which already supports multiple different architectures, including arm64. No need to build anything yourself.

Just ensure that the Fabric peer is configured for the address of the running CouchDB instance that it will use for its world-state database. See the Fabric documentation for details. There is an example Docker Compose YAML file including CouchDB in the fabric-samples repository, and used the the test-network there.