[DRE-maint] Bug#903074: foodcritic FTBFS: update Build-Depends: ruby-ronn -> ronn

[Helmut Grohne]

Source: foodcritic
Version: 13.1.1-1
Severity: serious

Since ronn got split out of ruby-ronn, foodcritic fails to build from
source. It was not possible to have ruby-ronn temporarily depend on
ronn, because that would have created a dependency cycle. Please update
Build-Depends and replace ruby-ronn with ronn as foodcritic uses the
command line tool.

Helmut