Increase maxComponentCount (because VTTShell doesn't) (#259)

We set it to 4 because VTT will _decrease_ it, but not increase it.
We can't remove it because vttlib will carp.

Author: DHowett

sources/vtt_data/CascadiaCode.ttx

@@ -39128,7 +39128,7 @@ Smooth()
     <maxStackElements value="717"/>
     <maxSizeOfInstructions value="3971"/>
     <maxComponentElements value="3"/>
-    <maxComponentDepth value="2"/>
+    <maxComponentDepth value="4"/>
   </maxp>
 
 </ttFont>