Merge pull request #210 from edx/diana/pin-ddtrace

docs: Add link to relevant ticket.

Author: dianakhuang

playbooks/roles/edxapp/defaults/main.yml

@@ -644,6 +644,7 @@ EDXAPP_DATADOG_INFERRED_SERVICES_ENABLE: true
 
 # We are seeing issues with celery processing tasks with later versions of ddtrace,
 # so this pin is in place until we understand what's going on.
+# See ticket: https://github.com/edx/edx-arch-experiments/issues/1060
 EDXAPP_DDTRACE_PIP_SPEC: 'ddtrace==3.8.1'
 
 EDXAPP_ORA2_FILE_PREFIX: '{{ COMMON_ENVIRONMENT }}-{{ COMMON_DEPLOYMENT }}/ora2'