MM-39314: Pre-package Playbooks 1.21.0 (#18935)

Makefile

@@ -117,7 +117,7 @@ PLUGIN_PACKAGES += mattermost-plugin-channel-export-v1.0.0
 PLUGIN_PACKAGES += mattermost-plugin-custom-attributes-v1.3.0
 PLUGIN_PACKAGES += mattermost-plugin-github-v2.0.1
 PLUGIN_PACKAGES += mattermost-plugin-gitlab-v1.3.0
-PLUGIN_PACKAGES += mattermost-plugin-playbooks-v1.20.2
+PLUGIN_PACKAGES += mattermost-plugin-playbooks-v1.21.0
 PLUGIN_PACKAGES += mattermost-plugin-jenkins-v1.1.0
 PLUGIN_PACKAGES += mattermost-plugin-jira-v2.4.0
 PLUGIN_PACKAGES += mattermost-plugin-nps-v1.1.0