Bump prepackage Gitlab plugin version to 1.8.1 (#26274)

Co-authored-by: Michael Kochell <6913320+mickmister@users.noreply.github.com>

server/Makefile

@@ -149,7 +149,7 @@ TEMPLATES_DIR=templates
 PLUGIN_PACKAGES ?= $(PLUGIN_PACKAGES:)
 PLUGIN_PACKAGES += mattermost-plugin-calls-v0.25.0
 PLUGIN_PACKAGES += mattermost-plugin-github-v2.2.0
-PLUGIN_PACKAGES += mattermost-plugin-gitlab-v1.8.0
+PLUGIN_PACKAGES += mattermost-plugin-gitlab-v1.8.1
 PLUGIN_PACKAGES += mattermost-plugin-playbooks-v1.39.1
 PLUGIN_PACKAGES += mattermost-plugin-jira-v4.1.0
 PLUGIN_PACKAGES += mattermost-plugin-nps-v1.3.3