Gutenframe: Add the snackbar to the list of link elements that should…

… open in the parent frame. (#34104)

Gutenberg v5.9 introduced the snackbar, a new way to display notices to users in the block editor.

This PR ensures the View Post anchor of snackbars will open their link in the parent frame, as we already do with the same link in existing Gutenberg admin notices.

apps/wpcom-block-editor/src/calypso/iframe-bridge-server.js

@@ -538,7 +538,8 @@ function handleGoToAllPosts( calypsoPort ) {
  */
 function openLinksInParentFrame() {
 	const viewPostLinkSelectors = [
-		'.components-notice-list .is-success .components-notice__action.is-link', // View Post link in success notice
+		'.components-notice-list .is-success .components-notice__action.is-link', // View Post link in success notice, Gutenberg <5.9
+		'.components-snackbar-list .components-snackbar__content a', // View Post link in success snackbar, Gutenberg >=5.9
 		'.post-publish-panel__postpublish .components-panel__body.is-opened a', // Post title link in publish panel
 		'.components-panel__body.is-opened .post-publish-panel__postpublish-buttons a.components-button', // View Post button in publish panel
 	].join( ',' );