docs: Add NiFi fixes

Author: Techassi

modules/ROOT/partials/release-notes/release-26.3.adoc

@@ -209,6 +209,11 @@ Fixed in https://github.com/stackabletech/issues/issues/821[issues#821].
 Add the `hbase.rest.endpoint` field to the restserver rolegroup ConfigMap for advertising the REST servers.
 Fixed in https://github.com/stackabletech/hbase-operator/pull/716[hbase-operator#716].
 
+===== Apache NiFi
+
+The operator now utilizes the `.spec.clusterConfig.authorization.opa.package` field instead of hard-coding the OPA package name to `nifi`.
+Fixed in https://github.com/stackabletech/nifi-operator/pull/881[nifi-operator#881].
+
 
 ==== Supported versions