refactor: use maps.Copy for cleaner map handling

[pullmerge]

Before asking for reviews, here is a check list of the most common things you might need to consider:

• updating the Changelog
• writing unit tests
• checking if your changes affect other coins or tokens in unintended ways
• testing on multiple environments (Qt, Android, ...)
• having an AI review your changes

Optimize code using a more modern writing style.

[benma]

CI failed with

golangci-lint --version
golangci-lint has version 1.61.0 built with go1.23.1 from a1d6c560 on 2024-09-09T17:44:42Z
+ golangci-lint config verify
+ golangci-lint run
util/logging/logging-stack-hook.go:17: File is not `goimports`-ed (goimports)
import "maps"