ci: cache pytype-related files between runs

9 jobs for topic/default/pytype-cache in 20 minutes and 9 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Test
passed doc #55017

00:00:28

passed flake8 #55011

00:00:22

passed pytype #55687
manual

00:15:53

passed tests-py2-cext #55013

00:04:14

passed tests-py2-pure #55014

00:04:15

passed tests-py3-cext #55015

00:03:23

passed tests-py3-pure #55016

00:02:33

passed pytype #55018
manual

00:16:11

passed pytype #55012
manual

00:15:44