Drop support for python 3.9

[Tranquility2]

Some future modules like in #762 don't play well with python 3.9.

Python 3.9 is near EOD, I suggest I'll start the deprecation process and we will release a new major (as this is a breaking change)

[alexanderankin]

sounds like v5 will drop support at the end of the year.

[alexanderankin]

i was about to file this as an issue but will just put this here instead:

Feature: reduce ci/cd redundancy (e.g. only run dood/dind tests for one python version)

we should pick a preferred python version and run the extra tests there only, this cuts down on CI/CD time.

I can see an argument for this being python3.11, i can also see an argument for it being the latest supported version.

we should maybe also consider adding python3.13 soon? i hardly use 3.12 anywhere still