The old printf-style string formatting syntax using '%' is not
recommended anymore. See for reference:
https://docs.python.org/3/library/stdtypes.html#printf-style-string-formatting
https://docs.sourcery.ai/Reference/Python/Default-Rules/replace-interpolation-with-fstring/

Python 3.6 introduced f-strings as a better alternative:
https://docs.python.org/3/reference/lexical_analysis.html#f-strings

Consequently switch to this new syntax for all strings.

Everytime we push a new commit to a branch, a new pipeline is created.
Often the pipeline for the previous commit has not finished yet, and
GitLab does not automatically cancel it. It consumes valuable build
time, even if we don't need the results anymore.
Adding a MR pipeline job to search for previous pipelines on the same
branch and cancel them explicitly.