`Signal`'s `providing_args` removal in 4.0

[g-as]

providing_args arg has been deprecated since 3.1.

https://docs.djangoproject.com/en/dev/releases/3.1/#id2

I can draft a PR provided some insights on:

• how to document the arguments
• whether to keep the providing_args for when version 2.2 and 3.0 (my suggestion would be no)

Since 4.0 beta 1 is out, should we add it to the test matrix?

[peppelinux]

@g-as thank you, go ahead!

[peppelinux]

@g-as have you seen this draft?
#292

consider to work on top of this if possibile, thank you

[g-as]

I'll take a look at it tomorrow!

[daggaz]

Any chance of a release including this any time soon?

[g-as]

1.3.6 was released two weeks ago:
https://github.com/IdentityPython/djangosaml2/releases/tag/v1.3.6
https://pypi.org/project/djangosaml2/

[daggaz]

Whoops! Was looking for a "version X" commit message, missed it. Sorry!

[g-as]

cheers