Add pytest-accept to a pixi developer environment

[Illviljan]

Is your feature request related to a problem?

pytest-accept is quite important for generation aggregations and quickly fixing changes in doctests.

For example:

xarray/xarray/util/generate_aggregations.py

Lines 1 to 14 in 58594f8

	"""Generate module and stub file for arithmetic operators of various xarray classes.
	For internal xarray development use only.
	Usage:
	python xarray/util/generate_aggregations.py
	pytest --doctest-modules xarray/{core,namedarray}/_aggregations.py --accept || true
	pytest --doctest-modules xarray/{core,namedarray}/_aggregations.py
	This requires [pytest-accept](https://github.com/max-sixty/pytest-accept).
	The second run of pytest is deliberate, since the first will return an error
	while replacing the doctests.
	"""

Describe the solution you'd like

Add pytest-accept to a pixi developer environment since it really isn't necessary for CI testing.

Describe alternatives you've considered

No response

Additional context

No response

[keewis]

I agree, we might need a dev environment that contains the full test env plus additional tools like pytest-accept or ipython/ipdb/black (and quite possibly another one that does include the typing feature).

[Illviljan]

Being new to pixi as well, I think also it would be nice for new contributors to only have to run pixi shell -e dev to get a working dev environment