Use ruff rules COM, F, I, RUF, UP (#17)

* Use pyupgrade (UP) rule

* Use pyflakes (F) rule

* Use isort (I) rule

* Use ruff-specific (RUF) rules

* Use flake8-commas (COM) rule

* Fix UP043 Unnecessary default type arguments

src/geo_assistant/agent/state.py

@@ -1,6 +1,7 @@
-from langchain.agents import AgentState
+from typing import NotRequired
+
 from geojson_pydantic import Feature
-from typing_extensions import NotRequired
+from langchain.agents import AgentState
 from pydantic import Field
 
 
@@ -8,5 +9,6 @@ class GeoAssistantState(AgentState):
     place: NotRequired[Feature | None] = None
     search_area: NotRequired[Feature | None] = None
     naip_png_path: NotRequired[str | None] = Field(
-        default=None, description="Path to the saved NAIP RGB PNG image"
+        default=None,
+        description="Path to the saved NAIP RGB PNG image",
     )