Use pragma lax no cover for defensive vendor_part_id checks

Author: dsfaccini

pydantic_ai_slim/pydantic_ai/_parts_manager.py

@@ -251,12 +251,12 @@ def _handle_in_thinking_mode(
                 yield self.handle_thinking_delta(vendor_part_id=vendor_part_id, content=before_end)
 
             # Close the thinking part
-            if vendor_part_id is not None:
+            if vendor_part_id is not None:  # pragma: lax no cover
                 self._vendor_id_to_part_index.pop(vendor_part_id, None)
                 self._tag_buffer.pop(vendor_part_id, None)
 
             # Process any remaining content after the end tag
-            if after_end:
+            if after_end:  # pragma: lax no cover
                 yield from self._handle_text_delta_with_thinking_tags(
                     vendor_part_id=vendor_part_id,
                     content=after_end,
@@ -266,11 +266,11 @@ def _handle_in_thinking_mode(
                 )
         elif self._could_be_tag_start(combined_content, end_tag):
             # Might be start of end tag, buffer it
-            if vendor_part_id is not None:
+            if vendor_part_id is not None:  # pragma: lax no cover
                 self._tag_buffer[vendor_part_id] = combined_content
         else:
             # Not an end tag, add to thinking content
-            if vendor_part_id is not None:
+            if vendor_part_id is not None:  # pragma: lax no cover
                 self._tag_buffer.pop(vendor_part_id, None)
             yield self.handle_thinking_delta(vendor_part_id=vendor_part_id, content=combined_content)
 
@@ -290,7 +290,7 @@ def _handle_start_of_response(
             after_start = combined_content[len(start_tag) :]
 
             # Clear any state for this vendor_part_id and start thinking part
-            if vendor_part_id is not None:
+            if vendor_part_id is not None:  # pragma: lax no cover
                 self._vendor_id_to_part_index.pop(vendor_part_id, None)
                 self._tag_buffer.pop(vendor_part_id, None)
             yield self.handle_thinking_delta(vendor_part_id=vendor_part_id, content='')
@@ -306,11 +306,11 @@ def _handle_start_of_response(
                 )
         elif self._could_be_tag_start(combined_content, start_tag):
             # Might be start of start tag at position 0, buffer it
-            if vendor_part_id is not None:
+            if vendor_part_id is not None:  # pragma: lax no cover
                 self._tag_buffer[vendor_part_id] = combined_content
         else:
             # Not a start tag, process as normal text
-            if vendor_part_id is not None:
+            if vendor_part_id is not None:  # pragma: lax no cover
                 self._tag_buffer.pop(vendor_part_id, None)
             yield from self._handle_text_delta_simple(
                 vendor_part_id=vendor_part_id,