Bump pypdf from 4.1.0 to 6.4.0 in /Oracle-23ai-RAG-Chatbot

Bumps [pypdf](https://github.com/py-pdf/pypdf) from 4.1.0 to 6.4.0.
- [Release notes](https://github.com/py-pdf/pypdf/releases)
- [Changelog](https://github.com/py-pdf/pypdf/blob/main/CHANGELOG.md)
- [Commits](py-pdf/pypdf@4.1.0...6.4.0)

---
updated-dependencies:
- dependency-name: pypdf
  dependency-version: 6.4.0
  dependency-type: direct:production
...

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

Author: dependabot[bot]

Oracle-23ai-RAG-Chatbot/requirements.txt

@@ -178,7 +178,7 @@ PyMuPDFb==1.23.22
 pynndescent==0.5.11
 pyOpenSSL==24.1.0
 pyparsing==3.1.2
-pypdf==4.1.0
+pypdf==6.4.0
 python-dateutil==2.9.0.post0
 python-json-logger==2.0.7
 python-jsonschema-objects==0.5.4