feat: Update PDFGenerator to include logo in header (#3311)

# Description

Please include a summary of the changes and the related issue. Please
also include relevant motivation and context.

## Checklist before requesting a review

Please delete options that are not relevant.

- [ ] My code follows the style guidelines of this project
- [ ] I have performed a self-review of my code
- [ ] I have commented hard-to-understand areas
- [ ] I have ideally added tests that prove my fix is effective or that
my feature works
- [ ] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged

## Screenshots (if appropriate):

backend/worker/quivr_worker/utils/pdf_generator/pdf_generator.py

@@ -34,9 +34,9 @@ class PDFGenerator(FPDF):
         )
 
     def header(self):
-        # # Logo
-        # logo_path = os.path.join(os.path.dirname(__file__), "logo.png")
-        # self.image(logo_path, 10, 10, 20)  # Adjust size as needed
+        # Logo
+        logo_path = os.path.join(os.path.dirname(__file__), "logo.png")
+        self.image(logo_path, 10, 10, 20)  # Adjust size as needed
 
         # Move cursor to right of image
         self.set_xy(20, 15)