Remove vestigial debug print statement in `walk_head_nodes` (#10718)
Remove vestigial debug print statement in `walk_head_nodes` (#10718)

* `graph`: Remove vestigial debug print statement in `walk_head_nodes`

* Revert whitespace changes

* Remove more debug print statements
explosion/spaCy,explosion/spaCy,explosion/spaCy,explosion/spaCy,explosion/spaCy,explosion/spaCy