tests: Update tests scripts.

tests.sh

@@ -1,5 +1,7 @@
 #! /bin/sh
 
+if [ -z "$GUIX_ENVIRONMENT" ]
+then
     echo " Setup ENV"
 
     python3 -m venv venv
@@ -7,6 +9,7 @@ python3 -m venv venv
     pip3 install -U pip
     pip3 install -r ./full-requirements.txt
     pip3 install -U -r ./full-requirements.txt
+fi
 
 echo " UNITTEST"