Add self-referencing properties field to Tool.Property

[LinNan1]

The Property class currently lacks a properties field, so it cannot represent nested object schemas.

File: ollama/_types.py

Change: Add a properties field to the Property class to enable recursive nesting.

ollama-python/ollama/_types.py

Lines 372 to 384 in fa85099

	class Property(SubscriptableBaseModel):
	model_config = ConfigDict(arbitrary_types_allowed=True)
	type: Optional[Union[str, Sequence[str]]] = None
	items: Optional[Any] = None
	description: Optional[str] = None
	enum: Optional[Sequence[Any]] = None
	properties: Optional[Mapping[str, Property]] = None
	parameters: Optional[Parameters] = None
	function: Optional[Function] = None

      class Property(SubscriptableBaseModel):
        model_config = ConfigDict(arbitrary_types_allowed=True)

        type: Optional[Union[str, Sequence[str]]] = None
        items: Optional[Any] = None
        description: Optional[str] = None
        enum: Optional[Sequence[Any]] = None
+       properties: Optional[Mapping[str, 'Property']] = None

      properties: Optional[Mapping[str, Property]] = None

This enables arbitrary-depth nesting using Pydantic's forward reference. No breaking changes.