Add reno for disabling Ironic Prometheus Exporter

Author: MoteHue

releasenotes/notes/disable-ironic-prometheus-exporter-daf2dda149466a2e.yaml

@@ -0,0 +1,9 @@
+---
+issues:
+  - |
+    The Ironic Prometheus Exporter has been (temporarily) disabled. See bug for
+    details: https://bugs.launchpad.net/kolla-ansible/+bug/2062401
+upgrade:
+  - |
+    The Ironic Prometheus Exporter has been (temporarily) disabled. See bug for
+    details: https://bugs.launchpad.net/kolla-ansible/+bug/2062401