Use plus icon from @wordpress/icons

[MAILPOET-4287]

mailpoet/assets/css/src/components-automation-editor/_add-step-button.scss

@@ -3,6 +3,7 @@
   background: #dcdcde;
   border: none;
   border-radius: 2px;
+  fill: #2b3337;
   height: 16px;
   margin: 0;
   outline: 4px solid #fbfbfb;

mailpoet/assets/js/src/automation/editor/components/icons/index.ts

@@ -1,4 +1,3 @@
 export { DelayIcon } from './delay';
 export { EmailIcon } from './email';
-export { PlusIcon } from './plus';
 export { TriggerIcon } from './trigger';

mailpoet/assets/js/src/automation/editor/components/icons/plus.tsx

@@ -1,14 +0,0 @@
-export function PlusIcon(): JSX.Element {
-  return (
-    <svg
-      width="16"
-      height="16"
-      viewBox="0 0 16 16"
-      fill="none"
-      xmlns="http://www.w3.org/2000/svg"
-    >
-      <path d="M4 8H12" stroke="#2C3338" />
-      <path d="M8 4L8 12" stroke="#2C3338" />
-    </svg>
-  );
-}

mailpoet/assets/js/src/automation/editor/components/workflow/add-step-button.tsx

@@ -1,7 +1,7 @@
 import { useContext } from 'react';
 import { __unstableCompositeItem as CompositeItem } from '@wordpress/components';
+import { Icon, plus } from '@wordpress/icons';
 import { WorkflowCompositeContext } from './context';
-import { PlusIcon } from '../icons';
 
 type Props = {
   onClick?: (element: HTMLButtonElement) => void;
@@ -21,7 +21,7 @@ export function AddStepButton({ onClick }: Props): JSX.Element {
         onClick(button);
       }}
     >
-      <PlusIcon />
+      <Icon icon={plus} size={16} />
     </CompositeItem>
   );
 }