Bump prepackage GitLab plugin version to 1.8.0 (#25789)

server/Makefile

@@ -155,7 +155,7 @@ PLUGIN_PACKAGES += mattermost-plugin-channel-export-v1.0.0
 PLUGIN_PACKAGES += mattermost-plugin-confluence-v1.3.0
 PLUGIN_PACKAGES += mattermost-plugin-custom-attributes-v1.3.1
 PLUGIN_PACKAGES += mattermost-plugin-github-v2.1.7
-PLUGIN_PACKAGES += mattermost-plugin-gitlab-v1.7.0
+PLUGIN_PACKAGES += mattermost-plugin-gitlab-v1.8.0
 PLUGIN_PACKAGES += mattermost-plugin-playbooks-v1.39.1
 PLUGIN_PACKAGES += mattermost-plugin-jenkins-v1.1.0
 PLUGIN_PACKAGES += mattermost-plugin-jira-v4.1.0