RF: Install ci rules utilities through pip

rules/fsl-ci-build-rules.yml

@@ -60,7 +60,7 @@ trigger-staging-package-build:
            $FSL_CI_SKIP_ALL                      == null'
 
   script:
-    - python3 ./.ci_rules/scripts/trigger_package_build.py
+    - trigger_package_build
 
 
 # Open a MR on a recipe repository to update the
@@ -84,7 +84,7 @@ update-conda-recipe:
            $FSLCONDA_SKIP_RECIPE_UPDATE == null'
 
   script:
-    - python3 ./.ci_rules/scripts/update_conda_recipe.py
+    - update_conda_recipe
 
 
 #######################################################
@@ -183,7 +183,7 @@ update-conda-recipe:
     - echo "DEPLOY=$DEPLOY"                           >> build.env
     - echo "FSLCONDA_REPOSITORY=$FSLCONDA_REPOSITORY" >> build.env
     - echo "FSLCONDA_REVISION=$FSLCONDA_REVISION"     >> build.env
-    - python3 ./.ci_rules/scripts/build_conda_package.py
+    - build_conda_package
 
   # Platform-specific jobs will direct their outputs
   # into "noarch", "linux" and "macos" sub-directories

rules/fsl-ci-deploy-rules.yml

@@ -47,4 +47,4 @@ deploy-conda-package:
     - build-linux-cuda-11.0-conda-package
     - run-unit-tests
   script:
-    - bash ./.ci_rules/scripts/deploy_conda_package.sh
+    - deploy_conda_package

rules/fsl-ci-job-template.yml

@@ -59,10 +59,10 @@
         git config --global "url.${giturl}/.insteadOf" "git@git.fmrib.ox.ac.uk:";
       fi
 
-    # Download a copy of the common CI rules
-    # repo (this repo)
-    - git clone ${CI_RULES_REPOSITORY} ./.ci_rules
-    - export PYTHONPATH=${PWD}/.ci_rules/utils
+    # Install the CI rules utilities (this repo).
+    # It is assumed that "python" is provided by
+    # the miniconda base environment
+    - python -m pip install git+${CI_RULES_REPOSITORY}
 
     # Isolate conda configuration to unique
     # config dir