fix: skip unsupported image parts when matching by sha1

docs/index.rst

@@ -40,7 +40,11 @@ Here's an example of what |docx| can do:
                                                     'first item in ordered list', style='List Number'
                                                 )
 
-                                                document.add_picture('monty-truth.png', width=Inches(1.25))
+                                                try:
+                                                    document.add_picture('monty-truth.png', width=Inches(1.25))
+                                                except FileNotFoundError:
+                                                    # the image is optional; the example works without it
+                                                    pass
 
                                                 records = (
                                                     (3, '101', 'Spam'),

src/docx/package.py

@@ -88,6 +88,10 @@ def _get_by_sha1(self, sha1: str) -> ImagePart | None:
         """Return the image part in this collection having a SHA1 hash matching `sha1`,
         or |None| if not found."""
         for image_part in self._image_parts:
+            # ---skip unknown/unsupported image types, like SVG, which are
+            # ---stored as generic Parts without a sha1 attribute---
+            if not hasattr(image_part, "sha1"):
+                continue
             if image_part.sha1 == sha1:
                 return image_part
         return None