docs: Add comment explaining ImageBytes/PdfBytes exclusion

Add clarifying comment in type_map explaining why ImageBytes and
PdfBytes are not included in the dbt type mapping. While these types
exist in Feast, dbt manifests only expose generic BYTES type without
semantic information to distinguish between regular bytes, images, or
PDFs.

Example: A dbt model with image and PDF columns both appear as
'BYTES' in the manifest, making ImageBytes/PdfBytes types unmappable
from dbt artifacts.

Addresses feedback from PR feast-dev#5827 review (franciscojavierarceo).

Signed-off-by: yassinnouh21 <[email protected]>

Author: YassinNouh21

sdk/python/feast/dbt/codegen.py

@@ -140,7 +140,9 @@ def _get_feast_type_name(feast_type: Any) -> str:
         base_type_name = _get_feast_type_name(base_type)
         return f"Array({base_type_name})"
 
-    # Map type objects to their names
+    # Map type objects to their names.
+    # Note: ImageBytes and PdfBytes are excluded since dbt manifests only expose
+    # generic BYTES type without semantic information about binary content.
     type_map = {
         String: "String",
         Int32: "Int32",