Window(fix[select_layout]): use -p flag for previous layout, not -o

why: select-layout -o restores the old/saved layout (undo), while -p
cycles to the previous layout preset. The previous_layout parameter
was sending -o instead of -p. Verified in cmd-select-layout.c:89.
what:
- Change -o to -p for previous_layout flag
- Update docstring to reference correct flag

Author: tony

src/libtmux/window.py

@@ -511,7 +511,7 @@ def select_layout(
 
             .. versionadded:: 0.45
         previous_layout : bool, optional
-            Move to the previous layout (``-o`` flag).
+            Move to the previous layout (``-p`` flag).
 
             .. versionadded:: 0.45
 
@@ -542,7 +542,7 @@ def select_layout(
             cmd.append("-n")
 
         if previous_layout:
-            cmd.append("-o")
+            cmd.append("-p")
 
         if layout:  # tmux allows select-layout without args
             cmd.append(layout)