configure_graphics: Fix layout in global config

Fixes a regression where the global config takes up a lot of extra space.

src/yuzu/configuration/configure_graphics.ui

@@ -149,7 +149,7 @@
         <item>
          <widget class="QWidget" name="bg_layout" native="true">
           <property name="sizePolicy">
-           <sizepolicy hsizetype="MinimumExpanding" vsizetype="MinimumExpanding">
+           <sizepolicy hsizetype="Preferred" vsizetype="Preferred">
             <horstretch>0</horstretch>
             <verstretch>0</verstretch>
            </sizepolicy>