Add Elasticsearch migrations issue to our release notes (#51832)

Co-authored-by: Vanessa <vgrl@github.com>

data/release-notes/enterprise-server/3-13/0.yml

@@ -183,7 +183,9 @@ sections:
       For an instance in a cluster configuration and with GitHub Actions enabled, restoring a cluster from backup requires targeting the primary DB node.
     - |
       Memory utilization may increase after the upgrade. During periods of high traffic, interruptions in service may occur due to insufficient memory allocations for internal components.
-
+    - |
+      Following an upgrade, Elasticsearch search migrations are sometimes incorrectly reported as failing in the audit log, even though the migrations completed successfully. [Updated: 2024-08-02]
+      
   deprecations:
     # https://github.com/github/releases/issues/2732
     - |

data/release-notes/enterprise-server/3-13/2.yml

@@ -165,3 +165,5 @@ sections:
       Running a config apply as part of the steps for [Replacing a node in an emergency](/admin/monitoring-managing-and-updating-your-instance/configuring-clustering/replacing-a-cluster-node#replacing-a-node-in-an-emergency) may fail with errors if the node being replaced is still reachable. If this occurs, shutdown the node and repeat the steps.
     - |
       If a hotpatch upgrade requires the `haproxy-frontend` service to be restarted, the restart will hang if there are existing long-lived connections, such as browser web sockets or Git operations. No new connections will be accepted for up to 5 minutes. Any existing unfinished connections at this time will be disconnected.
+    - |
+      Following an upgrade, Elasticsearch search migrations are sometimes incorrectly reported as failing in the audit log, even though the migrations completed successfully. [Updated: 2024-08-02]