remove requirement_dev.txt from project

[p-r-a-v-i-n]

since we are using pyproject.toml depending on extra file for dependency is redundant. we should use the power of pyproject.toml to take care of it.

according PEP 735 we can use dependency groups which is more convenient.

[github-actions]

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[tim-schilling]

Thank you for iterating on this. I still have some open questions unfortunately. I'm sorry for the slow responses.

[p-r-a-v-i-n]

Hey @tim-schilling ,
I like working with you. I like your insights. and your feedback really helps me understand things even more better.

Currently I have some thoughts in my mind.

1. I have strong believe that for building docs it will pick pip install --group docs, but it just assumption no strong evidence ( bcs no experience).
2. I'm not sure whether this changes are absolutely requires at this movement. Honestly, I submitted this PR for my personal milestone , and I understood personal milestone should not be greater than the project need. Project requirement should be the first priority.

I'm happy to iterate as per the feedback. and I'm happy answer/discuss questions. Thank you.

[tim-schilling]

Suggested change

	pip install --group dev
	pip install --group dev --group docs

This is referring to the documentation dependencies. I suspect we need to change all the references? Or have the dev group also include the docs group.

[tim-schilling]

This is a different workflow than I'm used to, though I think it's close to a mergeable state. @matthiask or I will need to check on the readthedocs integration after this gets merged. It's probably a good idea regardless since it's been a while since I've looked at that.

I'd like to get opinions from @django-commons/django-debug-toolbar on whether this is +1, 0 or -1 type thing. For me, I'm very used to pip install -r requirements_dev.txt. I suspect I will get tripped up by this change for a while. That said, I'm a 0 on it. I like the docs dependency group for read the docs.