Update debian/changelog, version file, and release-notes/3.9.4.md for 3.9.4 release

Author: hubot

debian/changelog

@@ -1,3 +1,15 @@
+github-backup-utils (3.9.4) UNRELEASED; urgency=medium
+
+ ### Bug Fixes
+
+* On an instance with Actions enabled, incorrect backup and restore settings prevented the storage container name from being restored. This made the logs from that container inaccessible, and caused Actions to create a new storage container in a different location. 
+
+### Backups and Disaster Recovery
+
+When a NFS mount is detected for snapshots on backup hosts, backup logs will show a warning to notify the user that such a setup may incur performance issues as highlighted in [storage requirements](https://github.com/github/backup-utils-private/blob/master/docs/requirements.md#storage-requirements) documentation.
+
+ -- ghes-releases-team  Wed, 01 Nov 2023 14:28:19 +0000
+
 github-backup-utils (3.9.4) UNRELEASED; urgency=medium
 
  * On an instance with Actions enabled, incorrect backup and restore settings prevented the storage container name from being restored. This made the logs from that container inaccessible, and caused Actions to create a new storage container in a different location.