[Deprecation] Update package for dbt Fusion and dbt Core 1.10.6 compatibility

[fivetran-jamie]

Copied from fivetran/dbt_amazon_ads #25.

Address the following deprecation warnings that will become errors in upcoming releases of dbt Fusion:

loaded_at_field

Example deprecation message:

> dbtf compile 2>&1 | grep -B 1 "src_jira"
warning: (will error post beta) dbt1060: Ignored unexpected key `"loaded_at_field"`. YAML path: `loaded_at_field`.
  --> dbt_packages/jira_source/models/src_jira.yml:11:5

loaded_at_field in the src.yml needs to be nested under config:, similar to freshness now.

test arguments

Example deprecation message:

  dbt0102: Deprecated test arguments: ["combination_of_columns"] at top-level detected.
  Please migrate to the new format: https://docs.getdbt.com/reference/deprecations#missingargumentspropertyingenerictestdeprecation

For many of our models, we use the dbt_utils.unique_combination_of_columns test, which includes a combination_of_columns arg. This arg now needs to be nested under an arguments: property if we keep the tests. Otherwise, create a surrogate key for the affected models (hashed on the combination_of_columns fields) and use a generic unique/not_null test on this surrogate key.