tests: drop 3.7 compatibility for log -G missing parent edge

8 jobs for topic/default/3.7-graph-style in 9 minutes and 16 seconds (queued for 2 seconds)
Status Name Job ID Coverage
  Test
passed checks-py2 #208735

00:02:18

passed checks-py3 #208736

00:01:18

passed doc #208741

00:03:01

manual pytype #208734
allowed to fail manual
passed tests-py2-cext #208737

00:05:30

passed tests-py2-pure #208738

00:02:57

passed tests-py3-cext #208739

00:09:15

passed tests-py3-pure #208740

00:09:05