Add light public CTA box variant

styles/45-patterns-public-page-patterns.css

@@ -14,6 +14,10 @@
   margin-inline: auto;
 }
 
+.sg-public-page-pattern-call-to-action-box--light {
+  background: var(--surface-public-page-pattern-call-to-action-box-light);
+}
+
 .sg-public-page-pattern-call-to-action-box__action {
   display: flex;
 }