Revert "cibuild.sh: export PIP_USER and PYTHONUSERBASE"

This reverts commit 0a69e09f55813aa39db8ff0f2ddf9495b7c18fc0.
diff --git a/cibuild.sh b/cibuild.sh
index 80de270..d84a46a 100755
--- a/cibuild.sh
+++ b/cibuild.sh
@@ -44,9 +44,7 @@
 function python-tools {
   # Python User Env
   PIP_USER=yes
-  export PIP_USER
   PYTHONUSERBASE=$prebuilt/pylocal
-  export PYTHONUSERBASE
   add_path $PYTHONUSERBASE/bin
 }