docs: use apostrophes in *n't

gtk/gtksizegroup-private.h

@@ -25,7 +25,7 @@
  * GtkQueueResizeFlags:
  * @GTK_QUEUE_RESIZE_INVALIDATE_ONLY: invalidate all cached sizes
  *  as we would normally do when a widget is queued for resize,
- *  but don't actually add the toplevel resize container to the
+ *  but don’t actually add the toplevel resize container to the
  *  resize queue. Useful if we want to change the size of a widget
  *  see how that would affect the overall layout, then restore
  *  the old size.