Update pytest requirement from <8.2 to <8.4

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@1.0.0b3...8.3.1)

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

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

test-requirements.txt

@@ -10,4 +10,4 @@ python-glanceclient
 testtools
 python-dateutil
 boto3
-pytest<8.2
+pytest<8.4