Revert "Run pip check at end of devstack"

This reverts commit 79b8e79488.

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

inc/python

@@ -111,30 +111,6 @@ function disable_python3_package {
     $xtrace
 }
 
-
-function pip_check {
-    time_start "pip_check"
-
-    if [[ -n ${PIP_VIRTUAL_ENV:=} && -d ${PIP_VIRTUAL_ENV} ]]; then
-        local cmd_pip=$PIP_VIRTUAL_ENV/bin/pip
-    else
-        local cmd_pip
-        if python3_enabled; then
-            echo "Using python $PYTHON3_VERSION to check pip install because python3_enabled=True"
-            cmd_pip=$(get_pip_command $PYTHON3_VERSION)
-        else
-            echo "Using python $PYTHON2_VERSION to check pip install because python3_enabled=False"
-            cmd_pip=$(get_pip_command $PYTHON2_VERSION)
-        fi
-    fi
-
-    $cmd_pip check
-    result=$?
-
-    time_stop "pip_check"
-    return $result
-}
-
 # Wrapper for ``pip install`` to set cache and proxy environment variables
 # Uses globals ``OFFLINE``, ``PIP_VIRTUAL_ENV``,
 # ``PIP_UPGRADE``, ``*_proxy``,

stack.sh

@@ -1421,9 +1421,6 @@ fi
 # Check the status of running services
 service_check
 
-# Run pip check to make sure we're forward compatible with the pip depsolver.
-pip_check
-
 # Configure nova cellsv2
 # ----------------------