build(deps): bump pytest

Bumps [pytest](https://github.com/pytest-dev/pytest) from 8.4.1 to 9.0.3.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/main/CHANGELOG.rst)
- [Commits](pytest-dev/pytest@8.4.1...9.0.3)

---
updated-dependencies:
- dependency-name: pytest
  dependency-version: 9.0.3
  dependency-type: direct:production
...

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

Author: dependabot[bot]

packages/google-cloud-spanner/samples/samples/requirements-test.txt

@@ -1,4 +1,4 @@
-pytest==8.4.1
+pytest==9.0.3
 pytest-dependency==0.6.0
 mock==5.2.0
 google-cloud-testutils==1.6.4