net/foreman-proxy: update 2.5.4 -> 3.0.1

• update to version 3.0.1
• bump Puppet dependency to Puppet 7
• fix path in pkg-message
• take maintainership

Changes: https://github.com/theforeman/smart-proxy/compare/2.5.4...3.0.1
PR: 260019
Submitted by: Frank Wall <fw@moov.de>; junovitch (rebase on incremental update)