Update store_failures.md (#4937)

## What are you changing in this pull request and why?
<!---
Describe your changes and why you're making them. If related to an open 
issue or a pull request on dbt Core, then link to them here! 

To learn more about the writing conventions used in the dbt Labs docs,
see the [Content style
guide](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/content-style-guide.md).
-->

In the docs for [data
tests](https://docs.getdbt.com/docs/build/data-tests#storing-test-failures),
there's a note to clarify that `store_failures` replaces previous
failures for a given test. This note is missing from the docs for the
[`store_failures` resource
config](https://docs.getdbt.com/reference/resource-configs/store_failures),
so this PR adds it.

## Checklist
<!--
Uncomment when publishing docs for a prerelease version of dbt:
- [ ] Add versioning components, as described in [Versioning
Docs](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/single-sourcing-content.md#versioning-entire-pages)
- [ ] Add a note to the prerelease version [Migration
Guide](https://github.com/dbt-labs/docs.getdbt.com/tree/current/website/docs/docs/dbt-versions/core-upgrade)
-->
- [x] Review the [Content style
guide](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/content-style-guide.md)
so my content adheres to these guidelines.

website/docs/reference/resource-configs/store_failures.md

@@ -10,7 +10,7 @@ Optionally set a test to always or never store its failures in the database.
 - If specified as `true` or `false`, the
 `store_failures` config will take precedence over the presence or absence of the `--store-failures` flag.
 - If the `store_failures` config is `none` or omitted, the resource will use the value of the `--store-failures` flag.
-- When true, `store_failures` save all the record(s) that failed the test only if [limit](/reference/resource-configs/limit) is not set or if there are fewer records than the limit. `store_failures` are saved in a new table with the name of the test. By default, `store_failures` use a schema named `dbt_test__audit`, but, you can [configure](/reference/resource-configs/schema#tests) the schema to a different value. 
+- When true, `store_failures` saves all the record(s) that failed the test only if [limit](/reference/resource-configs/limit) is not set or if there are fewer records than the limit. `store_failures` are saved in a new table with the name of the test. A test's results will always **replace** previous failures for the same test, even if that test results in no failures. By default, `store_failures` uses a schema named `dbt_test__audit`, but, you can [configure](/reference/resource-configs/schema#tests) the schema to a different value. 
 
 This logic is encoded in the [`should_store_failures()`](https://github.com/dbt-labs/dbt-adapters/blob/60005a0a2bd33b61cb65a591bc1604b1b3fd25d5/dbt/include/global_project/macros/materializations/configs.sql#L15) macro.