Bump pypdf2 from 1.27.5 to 1.27.9 in /modules/sync

Bumps [pypdf2](https://github.com/py-pdf/PyPDF2) from 1.27.5 to 1.27.9.
- [Release notes](https://github.com/py-pdf/PyPDF2/releases)
- [Changelog](https://github.com/py-pdf/pypdf/blob/1.27.9/CHANGELOG)
- [Commits](https://github.com/py-pdf/PyPDF2/compare/1.27.5...1.27.9)

---
updated-dependencies:
- dependency-name: pypdf2
  dependency-type: direct:production
...

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

modules/sync/requirements.txt

@@ -3,7 +3,7 @@ lxml==4.9.1
 Markdown==2.6.6
 Pillow==9.3.0
 pymongo==3.3.0
-PyPDF2==1.27.5
+PyPDF2==1.27.9
 python-frontmatter==0.3.1
 PyYAML==5.4
 requests==2.31.0