store_failures_as missing from project schema

The [v1.7](https://github.com/dbt-labs/dbt-jsonschema/blob/main/schemas/1.7/dbt_project-1.7.json) and [latest](https://github.com/dbt-labs/dbt-jsonschema/blob/main/schemas/latest/dbt_project-latest.json) project schemas are missing valid values for [store_failures_as](https://docs.getdbt.com/reference/resource-configs/store_failures_as). Since this was valid from v1.7 onwards, it's correct to be missing in v1.5 and v1.6.

This causes a validation error (e.g. using `v8r`):
> Validating ./dbt_project.yml against schema from https://raw.githubusercontent.com/dbt-labs/dbt-jsonschema/main/schemas/latest/dbt_project-latest.json ...
>✖ ./dbt_project.yml is invalid
>
> ./dbt_project.yml#/tests/+store_failures_as must be object
> ./dbt_project.yml#/tests/+store_failures_as must be null
> ./dbt_project.yml#/tests/+store_failures_as must match exactly one schema in oneOf

According to the docs:
> The three supported values are:
> ephemeral — nothing stored in the database (default)
> table — test failures stored as a database table
> view — test failures stored as a database view
> You can configure it in all the same places as store_failures, including singular tests (.sql files), generic tests (.yml files), and dbt_project.yml.

Are there files for validating singular tests that I should also check for this bug?