Remove @author tags (#5601)

Our files are up to a decade old, and have churned so much, that the initial author of the file no longer has much meaning.

Furthermore, this will encourage developers to post to the developer group, rather than emailing Googlers (usually me) directly.

core/delete_area.js

@@ -7,7 +7,6 @@
 /**
  * @fileoverview The abstract class for a component that can delete a block or
  * bubble that is dropped on top of it.
- * @author kozbial@google.com (Monica Kozbial)
  */
 
 'use strict';