Add style param to Widget render method

tests/test_widget.py

@@ -1,10 +1,8 @@
-from contextlib import nullcontext as does_not_raise
-from decimal import Decimal
-
 import pytest
 
 from textual.app import App
 from textual.css.errors import StyleValueError
+from textual.css.styles import Styles
 from textual.geometry import Size
 from textual.widget import Widget
 
@@ -41,7 +39,7 @@ def test_widget_content_width():
             self.text = text
             super().__init__(id=id)
 
-        def render(self) -> str:
+        def render(self, styles: Styles) -> str:
             return self.text
 
     widget1 = TextWidget("foo", id="widget1")