ci: Set python version to 3.11

[roydahan]

Python 3.12 has some compatability issues with scylla-ccm. Setting the python version to 3.11 should workaround the issue for now.

[fruch]

@roydahan there two more appearances of the 3.x in the file you changed

[roydahan]

This solves the CI issue with CCM of tests that didn't run at all.
There are still some tests failures, but are unrelated.

e.g.:

'''
Error: Failures:
Error: MapperUDTTest.should_throw_error_when_table_is_altered_and_is_not_compatible_anymore:563
Expecting:
"Unrecognized name mainaddress"
to match pattern:
"(Undefined name mainaddress in selection clause|Undefined column name mainaddress.*)"
[INFO]
Error: Tests run: 120, Failures: 1, Errors: 0, Skipped: 4
'''

[roydahan]

@fruch / @Bouncheck please review and let's merge this one so we will have at least a working CI.

[fruch]

@fruch / @Bouncheck please review and let's merge this one so we will have at least a working CI.

CI seems to work o.k.,

5.4 - failing on some error message that seems to have change in some UDT failure.
2024.1.0~rc2 seems to be failing to start a cluster in 16 tests.

the rest of the version worked o.k.