Update pytest requirement from ==6.*,>=6.2.5 to ==7.*

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@6.2.5...7.0.1)

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

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

test_requirements.txt

@@ -1,3 +1,3 @@
-pytest==6.*,>=6.2.5
+pytest==7.*
 thumbor==7.*,>=7.0.6
 pytest-cov==3.*,>=3.0.0