Fix reference to removed V23 theme

app/src/main/res/values-v27/themes.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-    <style name="Base.V27.Theme.Tachiyomi.Light" parent="Base.V23.Theme.Tachiyomi.Light">
+    <style name="Base.V27.Theme.Tachiyomi.Light" parent="Base.Theme.Tachiyomi.Light">
         <item name="android:navigationBarColor">?attr/colorPrimary</item>
         <item name="android:windowLightNavigationBar">true</item>
     </style>