Summary

• Support JDBC v2 (0.7.2)
• Metabase 52.x + Java 21 CI (closes Run tests against Java 21 #276)
• Hopefully fixes the timezones issues (again) - related to Add fully fledged time zones support #200
• :convert-timezone feature is disabled for now. This feature looks like it is intended to be used with "wall clock" types, but we always have timezone information in ClickHouse by design; it's incredibly difficult to make the MB tests work in this case, and I am not sure that it is going to work properly with CH.
• Added max-open-connections configuration option; default is 100.

The CI uses a fork again (see metabase/metabase@v1.52.2.5...slvrtrn:metabase:0.52.x-ch); we've come a full circle. A few tests fail:

• Unclear how better-error-when-parameter-mismatch worked before, as was always generating an invalid CH query.
• iso-8601-text-fields has a ton of different hardcoded versions of it for different databases
• One branch of filter-test (MBQL datetime literal...) fails for an unknown reason and it's not clear how we can deduce what we are supposed to do in this case in our QP implementation.

Checklist

• Unit and integration tests covering the common scenarios were added
• A human-readable description of the changes was provided to include in CHANGELOG