bar: finalize drawer before recreating it

If the drawer previously existed, we need to .finalize() it, or we'll leak
its resources.

The comment about the stated reason for this is a little strange: we have
width and height setters here, can we not just set them and not re-create
the drawer at all? Thoughts welcome.

This is another leak that I found while looking for the source of #4821.

Signed-off-by: Tycho Andersen <tycho@tycho.pizza>

libqtile/bar.py

@@ -32,7 +32,7 @@
     import asyncio
     from typing import Any
 
-    from libqtile.backend.base import Internal, WindowType
+    from libqtile.backend.base import Drawer, Internal, WindowType
     from libqtile.command.base import ItemT
     from libqtile.config import Screen
     from libqtile.core.manager import Qtile
@@ -200,6 +200,7 @@ def __init__(self, widgets: list[_Widget], size: int, **config: Any) -> None:
         # bar as python is referring to the same list.
         self.widgets = widgets.copy()
         self.window: Internal | None = None
+        self.drawer: Drawer
         self._configured = False
         self._draw_queued = False
         self.future: asyncio.Handle | None = None
@@ -325,6 +326,8 @@ def _configure(self, qtile: Qtile, screen: Screen, reconfigure: bool = False) ->
 
         # We create a new drawer even if there's already a window to ensure the
         # drawer is the right size.
+        if hasattr(self, "drawer"):
+            self.drawer.finalize()
         self.drawer = self.window.create_drawer(width, height)
         self.drawer.clear(self.background)