Try using pip for slurm runner

.gitlab-ci.yml

@@ -9,8 +9,8 @@ variables:
 
 .singularity_before_script_anchor: &singularity_before_script_anchor
   before_script:
-    - pip3 install -r requirements.txt
-    - pip3 install -r requirements-dev.txt
+    - pip install -r requirements.txt
+    - pip install -r requirements-dev.txt
     - export BASETEMP=$RUN_BASE_DIR/$CI_COMMIT_REF_NAME/$CI_JOB_ID
     - echo $BASETEMP
     - mkdir -p $BASETEMP