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/workspace_drag_surface_svg.js

@@ -9,7 +9,6 @@
  * Blocks are moved into this SVG during a drag, improving performance.
  * The entire SVG is translated using CSS translation instead of SVG so the
  * blocks are never repainted during drag improving performance.
- * @author katelyn@google.com (Katelyn Mann)
  */
 
 'use strict';