Bump pypdf from 6.0.0 to 6.6.0 in /application/single_app

Bumps [pypdf](https://github.com/py-pdf/pypdf) from 6.0.0 to 6.6.0.
- [Release notes](https://github.com/py-pdf/pypdf/releases)
- [Changelog](https://github.com/py-pdf/pypdf/blob/main/CHANGELOG.md)
- [Commits](py-pdf/pypdf@6.0.0...6.6.0)

---
updated-dependencies:
- dependency-name: pypdf
  dependency-version: 6.6.0
  dependency-type: direct:production
...

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

Author: dependabot[bot]

application/single_app/requirements.txt

@@ -30,7 +30,7 @@ azure-identity==1.23.0
 azure-ai-contentsafety==1.0.0
 azure-storage-blob==12.24.1
 azure-storage-queue==12.12.0
-pypdf==6.0.0
+pypdf==6.6.0
 python-docx==1.1.2
 flask-executor==1.0.0
 PyMuPDF==1.25.3