Fix shell runner Python dependency install

.gitlab-ci.yml

@@ -5,6 +5,7 @@ stages:
 
 variables:
   PIP_CACHE_DIR: "$CI_PROJECT_DIR/.cache/pip"
+  CI_PYTHON_PACKAGES_DIR: "$CI_PROJECT_DIR/.ci-packages"
   APP_IMAGE_REPOSITORY: "$CI_REGISTRY_IMAGE/app"
   ASTERISK_IMAGE_REPOSITORY: "$CI_REGISTRY_IMAGE/asterisk"
   APP_IMAGE_TAG: "$CI_COMMIT_SHA"
@@ -22,8 +23,10 @@ variables:
   tags:
     - crm-shell
   before_script:
-    - $PYTHON_BIN -m pip install --upgrade pip
-    - $PYTHON_BIN -m pip install -r requirements.txt
+    - rm -rf "$CI_PYTHON_PACKAGES_DIR"
+    - mkdir -p "$CI_PYTHON_PACKAGES_DIR"
+    - $PYTHON_BIN -m pip install --target "$CI_PYTHON_PACKAGES_DIR" -r requirements.txt
+    - export PYTHONPATH="$CI_PYTHON_PACKAGES_DIR${PYTHONPATH:+:$PYTHONPATH}"
 
 test:
   extends: .python_job