Merge pull request #4366 from open-webui/dependabot/pip/backend/dev/pypdf-4.3.1

chore(deps): bump pypdf from 4.2.0 to 4.3.1 in /backend

backend/requirements.txt

@@ -41,7 +41,7 @@ langchain-chroma==0.1.2
 fake-useragent==1.5.1
 chromadb==0.5.4
 sentence-transformers==3.0.1
-pypdf==4.2.0
+pypdf==4.3.1
 docx2txt==0.8
 python-pptx==0.6.23
 unstructured==0.15.0