chore: update deps for py3.12

[jennifer-richards]

Updates requirements.txt to bump minimum versions to be officially compatible with py3.12 or beyond. The comments on the individual commits indicate what versions were declared to be supported by the version I bumped to.

These are the packages that did not have a py3.12-compatible declaration on pypi and where I couldn't tell conclusively from a quick look at the package repo. Tests all pass despite these and I haven't seen any failures in the very light manual poking I've done so far, so I expect most are bookkeeping rather than actual compatibility problems.

• defusedxml (indicates py3.9 support)
• django-widget-tweaks (1.5.1 supports py3.12/py3.13 but is not available on pypi yet)
• github3 (4.01 supports py3.11; is stale since 2023) candidate for dropping
• hashids (superseded by squids, but not compatible; only used for Person.photo_name() method that appears to be unused) candidate for dropping
• html5lib (stale since 2020, but used in tests)
• jwcrypto (py3.11, only used "aspirationally")
• mypy (stuck on 1.7.1 due to django-stubs; only py3.11 but seems to work, and we'll upgrade when we move to Django 5.x)
• oic (py3.11 but seems to work, only used in tests)
• pyang (only py3.11)
• python-magic (py3.9)
• pymemcache (py3.10 per pypi, but repo comments imply it's known to work with py3.12)
• rfc2html (py3.9)
• unidecode (py3.11; repo shows that py3.12 tests are likely passing)

A few packages needed some adjustments to work with the latest versions. This included boto3 (working around the checksum issue introduced in 1.36+), pytz (migrating meeting timezone/country fields to reflect changes in the available choices), and django-vite (adjusting the settings structure)

I dropped the djlint package because it appears to be struggling to find a maintainer and because I don't think we use it often/ever any more.

[jennifer-richards]

For the record: verified that boto3 works against R2 with the settings modified as in this PR. It seems that getting to 1.36.7 makes those settings not required. We're going to keep the settings changes though as a precaution.