chore: drop Python 3.10, bump dbt-core to 1.11

[axellpadilla]

Summary

• Drop Python 3.10 support (EOL October 2026)
• Bump minimum dbt-core from 1.10 to 1.11
• Update Python 3.11 as the new minimum version across CI, devcontainer, pre-commit, and documentation

Closes #758, #759, part of #719

[joshmarkovic]

@axellpadilla, thanks again for everything you're doing (You too, @Benjamin-Knight)!

Quick question on #762 before 1.11.0 goes GA: was dropping Python 3.10 driven by an actual dependency constraint or was it a proactive cleanup ahead of the October 2026 EOL?

dbt-core still supports 3.10 in both v1.11 and v1.12 (per the compatibility matrix at https://docs.getdbt.com/faqs/Core/install-python-compatibility), and dbt-core 1.12.0 on PyPI still ships requires-python = ">=3.10". So as it stands the adapter has a higher floor than the core it plugs into.

If there's a transitive dependency in the 1.11 set that needs 3.11+, that's completely fair and it'd be helpful to note it in the release notes. If it's purely proactive, would you consider keeping >=3.10 for 1.11 and dropping it in 1.12? That would let the adapter's Python support track dbt-core's, which is what most of us pin against.

[axellpadilla]

@joshmarkovic I just dont want EOL maintainability issues, that said, we could leave it theoretically and just don't test it, do you believe is really needed?. We aren't releasing dbt-sqlserver 1.11 on the date dbt core 1.11 was released so python 3.10 just makes no sense right now to continue maintaining, even very strange scientist packages already are compatible with 3.11 and AI should make very easy to upgrade private ones.