build: bump pytest-cov from 5.0.0 to 6.0.0 in /ResearchAssistant/App

Bumps [pytest-cov](https://github.com/pytest-dev/pytest-cov) from 5.0.0 to 6.0.0.
- [Changelog](https://github.com/pytest-dev/pytest-cov/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest-cov@v5.0.0...v6.0.0)

---
updated-dependencies:
- dependency-name: pytest-cov
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

ResearchAssistant/App/requirements.txt

@@ -6,7 +6,7 @@ azure-storage-blob==12.17.0
 python-dotenv==1.0.1
 azure-cosmos==4.9.0
 pytest-asyncio==0.25.0
-pytest-cov==5.0.0
+pytest-cov==6.0.0
 flake8==7.1.1
 black==24.10.0
 autoflake==2.3.1