fix: 9_Deep_Learning/requirements.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-KERAS-13743411
- https://snyk.io/vuln/SNYK-PYTHON-KERAS-13786416

Author: snyk-bot

9_Deep_Learning/requirements.txt

@@ -1,5 +1,5 @@
 matplotlib==3.2.1
 pandas==1.0.3
 numpy==1.18.4
-keras==2.4.3
+keras==3.12.0
 scikit_learn==0.23.2