Experimental skin fix, inspired by craftycodie's

Signed-off-by: TheKodeToad <TheKodeToad@proton.me>

launcher/ui/pages/instance/InstanceSettingsPage.ui

@@ -608,6 +608,16 @@
          </layout>
         </widget>
        </item>
+       <item>
+        <widget class="QCheckBox" name="legacySkinFix">
+         <property name="toolTip">
+          <string>Enables support for modern skins on old versions.</string>
+         </property>
+         <property name="text">
+          <string>Enable legacy skin fix</string>
+         </property>
+        </widget>
+       </item>
        <item>
         <spacer name="verticalSpacerMiscellaneous">
          <property name="orientation">