Prepping the dbt-duckdb tests to pass under the next release of DuckDB

[jwills]

Trying a new thing where I test out dbt-duckdb against the next release of DuckDB about a week-or-so before it comes out so I can get ahead of any bug fixes or updates I need in dbt-duckdb instead of having to scramble the day of the release to get stuff fixed.

Two things I needed to fix when I ran against 0.7.2-dev:

1. Partition columns (in the Hive-partitioned sense) are now VARCHAR types
2. There is a breaking change to the default division operator such that it will now return floats by default instead of ints; this can be overridden by setting the integer_division setting to true, which I am doing here b/c some of the dbt tests fail without this setting in place.