Fix: Swap run-csit.sh to Python3 robot framework

Issue-ID: RELENG-4523
Signed-off-by: Matthew Watkins <mwatkins@linuxfoundation.org>
Change-Id: I15ad8a147a669c503ea023f79cef101baf99c21f
diff --git a/csit/run-csit.sh b/csit/run-csit.sh
index 52ec218..f291e34 100755
--- a/csit/run-csit.sh
+++ b/csit/run-csit.sh
@@ -20,6 +20,12 @@
 
 # Branched from ccsdk/distribution to this repository Feb 23, 2021
 
+# Activate the virtualenv containing all the required libraries installed by prepare-csit.sh
+source_safely "${ROBOT3_VENV}/bin/activate"
+
+WORKDIR=$(mktemp -d --suffix=-robot-workdir)
+cd "${WORKDIR}"
+
 #
 # functions
 #
@@ -154,14 +160,8 @@
 # Run installation of prerequired libraries
 source_safely "${WORKSPACE}/prepare-csit.sh"
 
-# Activate the virtualenv containing all the required libraries installed by prepare-csit.sh
-source_safely "${ROBOT_VENV}/bin/activate"
-
-WORKDIR=$(mktemp -d --suffix=-robot-workdir)
-cd "${WORKDIR}"
-
 # Add csit scripts to PATH
-export PATH="${PATH}:${WORKSPACE}/docker/scripts:${WORKSPACE}/scripts:${ROBOT_VENV}/bin"
+export PATH="${PATH}:${WORKSPACE}/docker/scripts:${WORKSPACE}/scripts:${ROBOT3_VENV}/bin"
 export SCRIPTS="${WORKSPACE}/scripts"
 export ROBOT_VARIABLES=