Upgrade to newer versions of wagtail/django/python

[quadrismegistus]

Some notes here on wagtail/django version conflicts I ran into which we might want to solve later.

• wagtail 2.16 adds support for django 4
• wagtail 3.x changes its wagtail.core api, breaking our code
• wagtail is now up to 4.1.1

testing notes

• edit and create some pages with wagtail and check that things work as expected
• wagtail "chooser" has changed; check that you can add a person to the contributor page
• autocomplete requires configuring search; check that you can search people on the person snippet list, and that adding a person to contributor page works with partial names

test collection choices on archive search page:

• confirm all collections are present and default deselected collections display as expected
• confirm toggling collection filters works as expected
• add a new collection in the database with no works; confirm it shows up on on the archive list but is disabled (dimmed and can't be selected)

[mnaydan]

I poked around on Django and Wagtail and I think things look good! Two issues:

1. Partial search for snippets works, but only for names that I just created. Search is not working for old/existing snippets.
2. I'm not sure if this is related to the upgrade or I discovered a different bug but "True" is showing up as a collection after I added a new collection:
   

FYI, the new option to "Show counts" in Django is very handy.

[rlskoeser]

@mnaydan I must have forgotten to update the wagtail index! I made a note in the deploy notes that we need to do this when we deploy the update but with all the staging site woes I must have lost track. I just ran it now - partial search on older snippets should work now. (I also ran the command to update references - this is how wagtail keeps track of where an image or other resources is used).

I'll look into the weird "True" collection.

[mnaydan]

@rlskoeser thanks! the partial search is working now for snippets and images. Let me know whether the "True" collection is related to the upgrade or a separate bug.

[rlskoeser]

@mnaydan I think the "True" collection must be related to the upgrade - not sure what's causing it yet, but I remember making some changes to the relevant part of the code when I worked on the upgrade. I'm glad you spotted it!

[mnaydan]

Good news: "True" collection is no longer showing up, and selecting/deselecting yields results now as expected (no more collections=label in the URL for the case I describe above).

A couple problems:

• When I change the default deselected collections on admin, they're not appearing auto-deselected on the frontend.
• The new collection I added ('Second Test') did not show up at all until I added a work to it.

[rlskoeser]

@mnaydan just to check: could you / did you try the checks that didn't work with a hard refresh? The last modified time is based on the solr index, which the collection changes you made wouldn't affect so the browser cache could be obscuring this.

[mnaydan]

@rlskoeser ooh good call, I did not -- thank you for suggesting, I'll do that now.

[mnaydan]

@rlskoeser aha! That's exactly what it was. Sorry I didn't think of that! Those two checks are now working.

[rlskoeser]

@mnaydan oh good! Thanks for confirming. I do think it's ok for the last-modified to ignore these kinds of db changes, since it's not too likely to happen often.