Regenerated stubs for Gitaly proto v12.10.6

`lint.proto` is a new dependency among them.

Still the same problem with imports that have to be converted
to relative style.
4 jobs for topic/default/gitlab-12-10 in 1 minute and 28 seconds
Status Job ID Name Coverage
  Main
passed #80211
tests-current

00:00:17

98.0%
 
  Compat
passed #80212
install

00:00:22

failed #80214
allowed to fail
tests-hg-default

00:01:08

16.0%
passed #80213
tests-hg-stable

00:01:10

98.0%
 
Name Stage Failure
failed
tests-hg-default Compat
hgitaly/testhelpers.py      79     59    25%
--------------------------------------------
TOTAL 129 109 16%

=========================== short test summary info ============================
ERROR hgitaly/tests/test_commit.py
!!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!
========================= 1 warning, 1 error in 0.55s ==========================
ERROR: Job failed: exit code 1