test: Mark flake8 untested if it seems broken

https://bugzilla.redhat.com/show_bug.cgi?id=1591961

Author: scop

test/lib/completions/flake8.exp

@@ -11,6 +11,9 @@ proc teardown {} {
 setup
 
 
+# https://bugzilla.redhat.com/show_bug.cgi?id=1591961
+if {[assert_exec {flake8 --help} "" "" "untested"]} {
+
 assert_complete_any "flake8 "
 sync_after_int
 
@@ -20,5 +23,6 @@ sync_after_int
 assert_no_complete "flake8 --doesnt-exist="
 sync_after_int
 
+}
 
 teardown