Remove /support/learn (#17920)

7 jobs for master in 23 minutes and 30 seconds (queued for 1 second)
Status Job ID Name Coverage
  Test
passed #1400
check-po-msgfmt

00:01:22

passed #1399
lint-po

00:23:30

passed #1401
test-iuk

00:04:35

passed #1402
test-perl5lib

00:03:22

passed #1403
test-persistence-setup

00:06:04

passed #1404
test-python-doctest

00:00:23

passed #1405
test-whisperback

00:01:03