Bump pypdf from 6.0.0 to 6.1.1 (#111)

Bumps [pypdf](https://github.com/py-pdf/pypdf) from 6.0.0 to 6.1.1.
- [Release notes](https://github.com/py-pdf/pypdf/releases)
- [Changelog](https://github.com/py-pdf/pypdf/blob/main/CHANGELOG.md)
- [Commits](py-pdf/pypdf@6.0.0...6.1.1)

---
updated-dependencies:
- dependency-name: pypdf
  dependency-version: 6.1.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

requirements.txt

@@ -1,5 +1,5 @@
 langchain-couchbase==0.4.0
 streamlit==1.49.1
 langchain-community==0.3.29
-pypdf==6.0.0
+pypdf==6.1.1
 langchain-openai==0.3.33