update PyData Amsterdam deck (#34)

Signed-off-by: Panos Vagenas <[email protected]>

Author: vagenas

workshops/2025_09_24/README.md

@@ -4,7 +4,7 @@
 
 ## Slides
 
-See [docling_workshop.pptx](./docling_workshop.pptx) for the workshop slides.
+See [docling_workshop.pdf](./docling_workshop.pdf) for the workshop slides.
 
 ## Labs