same stage for template_testing

.gitlab-ci.yml

 stages:
-    - code_quality
-    - test
+    - template_testing
 
 include:
     - local: 'templates/python/testing/pytest/pytest.yml'
     - local: 'templates/python/code_quality/flake8/flake8.yml'
 
 pytest:
+    stage: template_testing
     variables:
         PROJECT_PATH: "tests/pytest_project"
         PYTHON_SETUP: "pip install ${PROJECT_PATH} pytest"
 
 flake8:
+    stage: template_testing
     variables:
-        IMAGE_TAG: "latest"
         PROJECT_PATH: "tests/flake8_project"
         PYTHON_SETUP: "pip install ${PROJECT_PATH} flake8"