Add 'duckdb' support

[ericmichael]

Please provide your name and company

Eric Martinez, 80/20 Jiu-Jitsu

Link the issue/feature request which this PR is meant to address

#66

Detail what changes this PR introduces and how this addresses the issue/feature request linked above. I encountered an error related to the + operator not being supported for adding an interval to a string in DuckDB.

The specific issue arises in the int_stripe__date_spine.sql model, where the dbt.dateadd function tries to add 1 day to the last_date_adjust variable, which is a string. This operation is not supported in DuckDB, causing the model to fail.

Since DuckDB uses Postgres syntax, we can simply handle it in the same way as Postgres is handled.

How did you validate the changes introduced within this PR? Validated locally. Additional changes may be required.

Which warehouse did you use to develop these changes? DuckDB.

Did you update the CHANGELOG?

• [x] Yes

Did you update the dbt_project.yml files with the version upgrade (please leverage standard semantic versioning)? (In both your main project and integration_tests)

• [x] Yes

Provide an emoji that best describes your current mood

:dancer:

Feedback

We are so excited you decided to contribute to the Fivetran community dbt package! We continue to work to improve the packages and would greatly appreciate your feedback on our existing dbt packages or what you'd like to see next.

PR Template

• Community Pull Request Template (default)

• Maintainer Pull Request Template (to be used by maintainers)