Replace the deprecated bzr package by breezy for the bzr protocol in makepkg.conf

Hi,

This MR aims to bring the change merged in upstream in pacman/pacman!78 (merged):

The bzr package isn't a thing anymore, every distributions (including Arch) replaced it by the breezy package.
However, makepkg is still explicitly looking for the bzr package to handle so named sources, generating the following error for PKGBUILDs that make the switch to breezy:

==> ERROR: Cannot find the bzr package needed to handle bzr sources.

This change makes the switch from bzr to breezy on makepkg side so we can do the same in our packages.
It could be great if a new release could be made after this MR is merged as this change is required to proceed with this ToDo list on our side.