Revert "build!: upgrade edxapp to Python 3.11"

[UsamaSadiq]

Reverts #28

[ormsbee]

😞 Can you share what it was that broke when you folks tried this latest upgrade? (I'm trying to figure out if there are any fixes that need to be backported into Redwood.

Thank you.

[ormsbee]

Got this from @jristau1984 in Slack:

There was a deploy that happened right before 3.11 that caused an issue and the two were muddled together during the incident investigation.

We did see a spike in xblock related errors for the 20 min it was live,. The Arbi-bom team is looking into that before re-enabling, but a root cause/fix is not yet known.

[robrap]

@UsamaSadiq and all: A reminder that all revert PRs should include as much information as possible about why we are reverting. This could include error details, etc. This will help both the community as well as our future selves, or others in 2U. Thank you!