Bump google-cloud-storage from 2.14.0 to 2.15.0

Bumps [google-cloud-storage](https://github.com/googleapis/python-storage) from 2.14.0 to 2.15.0.
- [Release notes](https://github.com/googleapis/python-storage/releases)
- [Changelog](https://github.com/googleapis/python-storage/blob/main/CHANGELOG.md)
- [Commits](googleapis/python-storage@v2.14.0...v2.15.0)

---
updated-dependencies:
- dependency-name: google-cloud-storage
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

requirements.txt

@@ -4,5 +4,5 @@ requests==2.31.0
 simpleaichat==0.2.2
 openai<1.0.0
 tiktoken==0.6.0
-google-cloud-storage==2.14.0
+google-cloud-storage==2.15.0
 google-auth==2.28.2