Revert "build gcip docker image with proper tagging" as tags should

reflect semver version

This reverts commit 703be80.

Author: ThomasSteinbach

.gitlab-ci.py

@@ -9,7 +9,6 @@
     python.isort(), python.flake8(), python.pytest(), python.evaluate_git_tag_pep404_conformity(),
     kaniko.execute(
         image_name="thomass/gcip",
-        image_tag=(PredefinedVariables.CI_COMMIT_TAG[1:] if PredefinedVariables.CI_COMMIT_TAG else PredefinedVariables.CI_COMMIT_REF_SLUG),
         enable_push=(PredefinedVariables.CI_COMMIT_TAG or PredefinedVariables.CI_COMMIT_BRANCH == "main"),
         dockerhub_user_env_var="DOCKER_USER",
         dockerhub_login_env_var="DOCKER_LOGIN",