Update and reorganise sphinx nitpick_ignore list

[dhomeier]

Description

Following up on #2237 (comment) this is adding a PyQt5.sip entry which raised a warning locally, although it did not seem to affect the CI.
Also cleaned up the entire list a bit, including removing all generic and internal object exceptions – hopefully all further warnings in our own docs can be fixed rather than ignored.
Apart from all the external Qt* references, what remains at this point are some BasicToolbar methods that are inherited from PyQt5.QtWidgets.QToolBar, and similar ones from matplotlib in glue.viewers; and thus also really outside of our own docs.
The module warnings for organization.rst appear to be due to no API documentation existing at that level, so why it would be nice to have actual references there, explicitly disabling the links also silences them.

As a note, as of Sphinx 4.1 (seems we have 4.4 everywhere) the entire list of external ignores could also be replaced by a more concise

nitpick_ignore_regex = [('py:class', r'PyQt5\.QtCore\.Q[A-Z][a-zA-Z]+'),
                        ('py:class', r'PyQt5\.QtWidgets\.Q[A-Z][a-zA-Z]+'),
                        ('py:class', r'Qt\.[A-Z][a-zA-Z]+'),
                        ('py:class', r'QPalette\.[A-Z][a-zA-Z]+'),
                        ('py:class', r'QWidget\.[A-Z][a-zA-Z]+'),
                        ('py:class', r'Q[A-Z][a-zA-Z]+')]

[codecov]

Codecov Report

Merging #2271 (8fe3006) into main (5604178) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #2271   +/-   ##
=======================================
  Coverage   88.07%   88.07%           
=======================================
  Files         247      247           
  Lines       23279    23279           
=======================================
  Hits        20502    20502           
  Misses       2777     2777           

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[astrofrog]

Looks good! Feel free to merge once the CI passes.

I'd also be fine with requiring Sphinx 4.1+ if you want to use the regexps for the nitpicks, so I'll leave that up to you (could be done in a follow-up PR).

[dhomeier]

I'd also be fine with requiring Sphinx 4.1+ if you want to use the regexps for the nitpicks, so I'll leave that up to you (could be done in a follow-up PR).

Probably don't need to make it a strict requirement – since older versions will just ignore the unknown config field, if someone wants to build with pre-4.1 they will merely see the bunch of warnings again.

[astrofrog]

Sounds good, feel free to merge once ready!

[dhomeier]

Thanks for reviewing!