Change default pdf loader (#1525)

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## Description
Change default loader from Advanced to light weight PyPDF loader

## Type of Change
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- [ ] Bug fix (non-breaking change that fixes an issue)
- [ ] New feature (non-breaking change that adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
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- [ ] Performance improvement
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cognee/infrastructure/loaders/LoaderEngine.py

@@ -27,11 +27,11 @@ class LoaderEngine:
 
         self.default_loader_priority = [
             "text_loader",
-            "advanced_pdf_loader",
             "pypdf_loader",
             "image_loader",
             "audio_loader",
             "unstructured_loader",
+            "advanced_pdf_loader",
         ]
 
     def register_loader(self, loader: LoaderInterface) -> bool: