PY-18816 Squash stub version changes into a single increment

python/src/com/jetbrains/python/psi/PyFileElementType.java

@@ -62,7 +62,7 @@ public class PyFileElementType extends IStubFileElementType<PyFileStub> {
   @Override
   public int getStubVersion() {
     // Don't forget to update versions of indexes that use the updated stub-based elements
-    return 63;
+    return 61;
   }
 
   @Nullable