I have successfully migrated it. In 3-4 days, I will create a user-guide for other users. I apologise for my previous comments if they sounded passive-aggressive. I did not meant them to be that way, but after reading them later, I realised they may look like it. Thank you everybody for your help/guidance. See you around.

Apparently, there are some modules missing in the "shared Pywikibot files (recommended setup)", and you guys are not responding other than rushing tool operators to migrate while back-end (from your side) is not completely ready yet.

tomorrow I will test the following file from https://en.wikipedia.org/wiki/User:Novem_Linguae/Essays/Toolforge_bot_tutorial#Example_cronjobs.yaml

There are a few independencies/contradictions in above linked help pages.
For one, as directed at https://wikitech.wikimedia.org/wiki/Help:Toolforge/Python#Kubernetes_python_jobs
I created bootstrap_venv.sh with exact same content as provided. After running the "toolforge-jobs run bootstrap-venv --command "cd $PWD && ./bootstrap_venv.sh" --image tf-python39 --wait" command, I get:
INFO: job 'bootstrap_venv' completed

I followed the directions given at:
https://wikitech.wikimedia.org/wiki/Help:Toolforge/Kubernetes
https://wikitech.wikimedia.org/wiki/Help:Toolforge/Python#Kubernetes_python_jobs
https://wikitech.wikimedia.org/wiki/Help:Toolforge/Jobs_framework
https://wikitech.wikimedia.org/wiki/Help:Toolforge/Pywikibot
and
https://en.wikipedia.org/wiki/User:Novem_Linguae/Essays/Toolforge_bot_tutorial

The tool was successfully migrated to buster on April 9, 2022. It was discussed here: https://wikitech.wikimedia.org/w/index.php?title=Help_talk:Toolforge/Pywikibot&diff=1967612&oldid=1966965

Maybe if we tell AWB to ignore other templates, and assign a character length, then it can be handled while editing?
I am not sure about other editors, but I generally check the changes in edit box. Especially if edit summary says "removed stub tag".
So whenever there is summary "replaced empty section with expand section", the editor should check for the section itself for the issues described by you.