Backport PR #50562 on branch 1.5.x (CI Ipython ci fixup again)
Backport PR #50562: CI Ipython ci fixup again
CI failure was related to the github quota when building the CI. The cache we're using now is different for each branch. Not sure how many website builds we can do before hitting the quota (assuming all CI workers use the same quota, that I don't think it's the case), but if it's just one, maybe it'd be good to increase the cache life to few hours instead of one. Please ping me if you see more web failures, and I'll have a look. ok, thanks for taking look!