Update dbt-tests-adapter requirement from ~=1.8.0b1 to ~=1.8.0b2

Updates the requirements on [dbt-tests-adapter](https://github.com/dbt-labs/dbt-core) to permit the latest version.
- [Release notes](https://github.com/dbt-labs/dbt-core/releases)
- [Changelog](https://github.com/dbt-labs/dbt-core/blob/main/CHANGELOG.md)
- [Commits](dbt-labs/dbt-core@v1.8.0b1...v1.8.0b2)

---
updated-dependencies:
- dependency-name: dbt-tests-adapter
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

dev_requirements.txt

@@ -1,4 +1,4 @@
-dbt-tests-adapter~=1.8.0b1
+dbt-tests-adapter~=1.8.0b2
 mypy==1.8.0  # patch updates have historically introduced breaking changes
 pre-commit~=3.6
 pytest~=7.4