DOC: correctly specify return type of figaspect

Author: DerWeh

lib/matplotlib/figure.py

@@ -3655,8 +3655,8 @@ def figaspect(arg):
 
     Returns
     -------
-    width, height : float
-        The figure size in inches.
+    size : (2,) array
+        The width and height of the figure in inches.
 
     Notes
     -----

lib/matplotlib/figure.pyi

@@ -418,4 +418,6 @@ class Figure(FigureBase):
         rect: tuple[float, float, float, float] | None = ...
     ) -> None: ...
 
-def figaspect(arg: float | ArrayLike) -> tuple[float, float]: ...
+def figaspect(
+    arg: float | ArrayLike,
+) -> np.ndarray[tuple[Literal[2]], np.dtype[np.float64]]: ...