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.

demos/blockfactory/block_option.js

@@ -10,7 +10,6 @@
  * option has a checkbox, a label, and a preview workspace through which to
  * view the block.
  *
- * @author quachtina96 (Tina Quach)
  */
 'use strict';