fix: bump keras from 3.9.0 to 3.9.1

Bumps [keras](https://github.com/keras-team/keras) from 3.9.0 to 3.9.1.
- [Release notes](https://github.com/keras-team/keras/releases)
- [Commits](keras-team/keras@v3.9.0...v3.9.1)

---
updated-dependencies:
- dependency-name: keras
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

requirements.txt

@@ -17,9 +17,9 @@ scikit-learn==1.6.1
 
 # Machine Learning Libraries:
 tensorflow==2.18.1
-keras==3.9.0
+keras==3.9.1
 tensorflow==2.18.1
-keras==3.9.0
+keras==3.9.1
 
 
 # Natural Language Processing Libraries: