Window.attached_pane: Use .filter

Author: tony

src/libtmux/window.py

@@ -730,9 +730,9 @@ def select(self) -> "Window":
     @property
     def attached_pane(self) -> t.Optional["Pane"]:
         """Return attached :class:`Pane`."""
-        for pane in self.panes:
-            if pane.pane_active == "1":
-                return pane
+        panes = self.panes.filter(pane_active="1")
+        if len(panes) > 0:
+            return panes[0]
         return None
 
     #