The issue itself was resolved with:
https://github.com/nix-community/home-manager/pull/6460
This patch only adds a test case to make sure we don't ever regress by
installing firefox and librewolf and floorp at the same time.
Closes: #6467
Signed-off-by: Ihar Hrachyshka <ihar.hrachyshka@gmail.com>
