Install required pip pkgs (#6906)

Author: krishung5

qa/L0_backend_python/test.sh

@@ -50,7 +50,6 @@ if [[ "$(< /proc/sys/kernel/osrelease)" == *microsoft* ]]; then
     export SERVER=${SERVER:=c:/tritonserver/bin/tritonserver.exe}
     export BACKEND_DIR=${BACKEND_DIR:=c:/tritonserver/backends}
     export MODELDIR=${MODELDIR:=c:/}
-    pip install requests virtualenv pytest
     TEST_WINDOWS=1
 else
     export DATADIR=${DATADIR:="/data/inferenceserver/${REPO_VERSION}"}
@@ -173,6 +172,8 @@ else
   pip3 install torch==1.13.0 -f https://download.pytorch.org/whl/torch_stable.html
 fi
 
+pip3 install pytest requests virtualenv
+
 prev_num_pages=`get_shm_pages`
 run_server
 if [ "$SERVER_PID" == "0" ]; then