build(deps): update pytest requirement from >=6.0.0 to >=9.1.1

Updates the requirements on [pytest](https://github.com/pytest-dev/pytest) to permit the latest version.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/main/CHANGELOG.rst)
- [Commits](pytest-dev/pytest@6.0.0...9.1.1)

---
updated-dependencies:
- dependency-name: pytest
  dependency-version: 9.1.1
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

requirements-testing.txt

@@ -1,4 +1,4 @@
-pytest>=6.0.0
+pytest>=9.1.1
 pytest-cov
 dataclasses; python_version < "3.7"
 pytest-forked