Future dependency upgrades: drop Python 3.7, add Python 3.12

[tw4l]

In #839, we decided to continue supporting Python 3.7 for the next release, which resulted in pinning a few older dependencies.

When we're ready for the next release following to drop Python 3.7 and add support for Python 3.12, we'll want to:

• Upgrade werkzeug (will require removing spaces in some tests, due to werkzeug >2.2.3 removing spaces in bodies
• Upgrade gevent (to 23.9.0 if the PSF supported httpbin still requires greenlet< 3, otherwise to latest and greenlet 3)
• Handle deprecation notices from tox

[bitsgalore]

I just ran into this as well. Many modern Linux distros now have have Python 3.12 or more recent as the default Python version. As an example I'm using Linux Mint 22.1, which is based on Ubuntu 24.04, and this currently uses Python 3.12.3. This makes me wonder when this will be updated?

As a test I manually removed the 3.12 requirement from the setup file, but this then triggered a build error from gevent (which is also mentioned above) .

[aquatix]

Hey all, thanks for this nifty project.

Debian 13 has been stable since early August, and has Python 3.13 by default, so this is getting a bit more urgent :)

[tw4l]

Python 3.12 support added in #958, which updates gevent and greenlet for Python 3.12. We should still update werkzeug, which is currently pinned to an older release due to pywb previously being stuck on Python < 3.12. To be seen at this point if werkzeug 3.x will require code changes besides in our test suite.