Bug#1123385: fenics-ffcx: FTBFS: FAILED test_cmdline.py::test_visualise - AssertionError: assert False

[Drew Parsons]

Source: fenics-ffcx
Followup-For: Bug #1123385
Control: tags -1 ftbfs
Control: reassign -1 python3-pygraphviz
Control: found -1 1.14-3
Control: affects -1 src:fenics-ffcx

This is Bug#1122280 in python3-pygraphviz, which uses neato from
graphviz and needs to declare the dependency.