Support Javascript UDFs

It seems that dbt-duckdb is not yet compatible with the [recently added Javascript UDFs](https://docs.getdbt.com/docs/dbt-versions/core-upgrade/upgrading-to-v1.12?version=2.0&name=v2#extensions-to-udfs)

_[ERROR]: Function 'decode_url' uses JavaScript, which is not supported on 'duckdb'_

```
User Error: dbt failed during project compilation.
Consider running `dbt debug` or `dbt compile` to get more information from dbt.
dbt.exceptions.ParsingError: Parsing Error
[ERROR]: Function 'decode_url' uses JavaScript, which is not supported on 'duckdb'.
(.venv) x@x datahub-dbt % sqlfluff lint models/cep/cep_customers.sql
```

```
Core:
- installed: 1.12.0
- latest: 1.12.0 - Up to date!

Plugins:
- snowflake: 1.12.0 - Up to date!
- duckdb: 1.10.1 - Up to date!
```

Start with the linked dbt 1.12 JavaScript-UDF upgrade notes and reproduce the failure with `dbt compile` or `dbt debug` using the shown versions; compare the DuckDB adapter's handling with the reported `decode_url` case. Done means a dbt project using a JavaScript UDF compiles under dbt-duckdb without the unsupported-on-duckdb error, and the existing `sqlfluff lint` check remains usable.

Written by the indexing model from the issue text.