Simplify grid bounds unpacking

Author: shubham0x13

adafruit_displayio_layout/layouts/grid_layout.py

@@ -378,10 +378,8 @@ def add_content(
          then the cell_anchor_point from the GridLayout will be used.
         :return: None"""
 
-        grid_x = grid_position[0]
-        grid_y = grid_position[1]
-        max_grid_x = self.grid_size[0]
-        max_grid_y = self.grid_size[1]
+        grid_x, grid_y = grid_position
+        max_grid_x, max_grid_y = self.grid_size
         if grid_x >= max_grid_x or grid_y >= max_grid_y:
             raise ValueError(
                 f"Grid position {grid_position} is out of bounds for grid size {self.grid_size}"