Update python.md (#5264)

Just a typo corrected in a script sample.

docs/docs/api/python/python.md

@@ -78,7 +78,7 @@ If the primary-key of an object is already known, retrieving it from the databas
 ```python
 from inventree.part import PartCategory
 
-category = PartCatgory(api, 10)
+category = PartCategory(api, 10)
 ```
 
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