Revert "Run pip check at end of devstack"

This reverts commit 79b8e79488a6268f37244188ab831e99a99648c8.

This is breaking things in various jobs, most notably because
we do not put constraints on linters - but we install
test-requirements which then can conflict with each other.

Change-Id: Ibc5603c61b38ce44db58fb27a27352f59123ad09
2 files changed