.gitlab-ci.yml: Fixed to not try to upgrade stuff

When trying to upgrade psutils the image requires gcc,
which it doesnt have.
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 5c73fa3..ef41496 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -29,8 +29,7 @@
 integration_tests:
   script:
     - dnf install -y findutils bzr
-    - pip3 install --upgrade pip
-    - pip3 install --upgrade .
+    - pip3 install .
     - git clone https://gitlab.com/BuildStream/buildstream-tests.git
     - cd buildstream-tests
     - ./run-test.sh --arg --colors test