audio/gnormalize: Deprecate and set expiration date to 2024-02-29

Last release in 2008, upstream is dead, depends on deprecated library
GTK2 and uses legacy workarounds that can potentially cause lossy
conversions. Redirect users to audio/rsgain and audio/cyanrip

PR: 276185
Approved by: portmgr (maintainer timeout, 2+ weeks)