fix: update pypdf version to 6.7.5 for compatibility

Author: liuruibin

pyproject.toml

@@ -52,7 +52,7 @@ dependencies = [
     "xlrd==2.0.2",
     "xlwt==1.3.0",
     "pymupdf==1.26.3",
-    "pypdf==6.7.4",
+    "pypdf==6.7.5",
     "pydub==0.25.1",
     "pysilk==0.0.1",
     "gunicorn==23.0.0",