gitlab: increase webpack memory limit

(cherry picked from commit 7555548)

pkgs/applications/version-management/gitlab/default.nix

@@ -89,7 +89,7 @@ let
 
       bundle exec rake gettext:po_to_json RAILS_ENV=production NODE_ENV=production
       bundle exec rake rake:assets:precompile RAILS_ENV=production NODE_ENV=production
-      bundle exec rake webpack:compile RAILS_ENV=production NODE_ENV=production NODE_OPTIONS="--max_old_space_size=2048"
+      bundle exec rake webpack:compile RAILS_ENV=production NODE_ENV=production NODE_OPTIONS="--max_old_space_size=3072"
       bundle exec rake gitlab:assets:fix_urls RAILS_ENV=production NODE_ENV=production
 
       runHook postBuild