Make this newer version of diffmerge installation work in Homebrew without warning?

[user1891]

Is it possible to make this newer version of diffmerge installation work in Homebrew without warning?

see https://support.sourcegear.com/viewtopic.php?p=88300#p88300

On my computer, I'm able to install diffmerge via Homebrew but it is the older version and it does complain it is "deprecated"!

$ brew upgrade diffmerge
$ brew info diffmerge
==> diffmerge ✔ (DiffMerge): 4.2.1.1013
Visually compare and merge files
https://www.sourcegear.com/diffmerge/
Deprecated because it does not pass the macOS Gatekeeper check! It will be disabled on 2026-09-01.
Installed (on request)
/opt/homebrew/Caskroom/diffmerge/4.2.1.1013 (28.7MB)
  Installed using the formulae.brew.sh API on 2026-04-10 at 11:05:23
From: https://github.com/Homebrew/homebrew-cask/blob/HEAD/Casks/d/diffmerge.rb
==> Requirements
Required: macOS >= 10.15 ✔
==> Artifacts
DiffMerge.app (App)
Extras/diffmerge.sh -> diffmerge (Binary)
Extras/diffmerge.1 (Manpage)
==> Caveats
diffmerge is built for Intel macOS and so requires Rosetta 2 to be installed.
You can install Rosetta 2 with:
  softwareupdate --install-rosetta --agree-to-license
Note that it is very difficult to remove Rosetta 2 once it is installed.

==> Downloading https://formulae.brew.sh/api/cask/diffmerge.json
==> Analytics
install: 140 (30 days), 406 (90 days), 2,400 (365 days)

$ brew doctor
Warning: Some installed casks are deprecated or disabled.
You should find replacements for the following casks:
  diffmerge
$ man diffmerge | grep Revision
65:       Revision 4.2.1.1013 stable