remove default before_script instead use extends construct

.gitlab-ci.yml

@@ -5,19 +5,22 @@ stages:
   - test
   - package
 
-before_script:
-    - cat /etc/issue
-    - python3 -V
-    - which python3
-    - python3 -m venv ../venv
-    - source ../venv/bin/activate
-    - which python3
-    - pwd
-    - pip install -U pip
-    - pip install ."[dev]"
-    - mpsd-quota --version
+.install_python_dependencies:
+  before_script:
+      - cat /etc/issue
+      - python3 -V
+      - which python3
+      - python3 -m venv ../venv
+      - source ../venv/bin/activate
+      - which python3
+      - pwd
+      - pip install -U pip
+      - pip install ."[dev]"
+      - mpsd-quota --version
+      - mpsd-quota --help
 
-before_build:
+.install_build_dependencies:
+  before_script:
     - cat /etc/issue
     - export DEBEMAIL="gitlab_ci@domain.com"
     - export DEBFULLNAME="Gitlab Runner" 
@@ -32,6 +35,7 @@ before_build:
 style:
   stage: test-style
   image: python:latest
+  extends: .install_python_dependencies
   script:
     - black --version
     - ruff --version
@@ -42,18 +46,21 @@ style:
 test3-09:
   stage: test
   image: python:3.9
+  extends: .install_python_dependencies
   script:
     - make test+coverage
 
 test3-10:
   stage: test
   image: python:3.10
+  extends: .install_python_dependencies
   script:
     - make test+coverage
 
 test3-11:
   stage: test
   image: python:3.11
+  extends: .install_python_dependencies
   script:
     - make test+coverage
 
@@ -62,6 +69,7 @@ test3-11:
 typing:
   stage: test-style
   image: python:latest
+  extends: .install_python_dependencies
   script:
     - make typing || /bin/true
 
@@ -69,8 +77,7 @@ typing:
 package:
   stage: package
   image: debian:bullseye
-  before_script:
-    - before_build
+  extends: .install_build_dependencies
   script:
     - make deb-package
   artifacts: