update prepackage boards to v7.4.3 (#21481)

Makefile

@@ -160,7 +160,7 @@ PLUGIN_PACKAGES += mattermost-plugin-jira-v2.4.0
 PLUGIN_PACKAGES += mattermost-plugin-nps-v1.2.0
 PLUGIN_PACKAGES += mattermost-plugin-welcomebot-v1.2.0
 PLUGIN_PACKAGES += mattermost-plugin-zoom-v1.6.0
-PLUGIN_PACKAGES += focalboard-v7.4.2
+PLUGIN_PACKAGES += focalboard-v7.4.3
 PLUGIN_PACKAGES += mattermost-plugin-apps-v1.1.0
 
 # Prepares the enterprise build if exists. The IGNORE stuff is a hack to get the Makefile to execute the commands outside a target