Issue #3467986 by doxigo: Undefined variable $sizes in gutenberg_form_node_form_alter()
(cherry picked from commit 989ab052)
93173a75 Issue #3467986: Undefined variable $sizes in gutenberg_form_node_form_alter()
Co-authored-by: Sohail Lajevardi 11443-doxigo@users.noreply.drupalcode.org