build(deps): bump renku from 2.7.0 to 2.8.0 in /docker/py

Bumps [renku](https://github.com/swissdatasciencecenter/renku-python) from 2.7.0 to 2.8.0.
- [Release notes](https://github.com/swissdatasciencecenter/renku-python/releases)
- [Changelog](https://github.com/SwissDataScienceCenter/renku-python/blob/develop/CHANGES.rst)
- [Commits](SwissDataScienceCenter/renku-python@v2.7.0...v2.8.0)

---
updated-dependencies:
- dependency-name: renku
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

docker/py/renku-requirements/requirements.txt

@@ -1,4 +1,4 @@
-renku==2.7.0
+renku==2.8.0
 pip==23.3.2
 sentry-sdk==1.38.0
 setuptools>=65.5.1