I've started seeing this recently in the supervisor logs every time HA Core backup runs. Not sure when it stated because the error isn't raised to core log and backup always succeeds (even though it fails). Core bug #144210
2025-05-09 10:50:47.846 INFO (MainThread) [supervisor.addons.addon] Building backup for add-on core_zwave_js
2025-05-09 10:50:47.851 ERROR (MainThread) [supervisor.addons.addon] Can't write tarfile <securetar._InnerSecureTarFile object at 0x7f97b304b770>: Error adding /data/addon_configs/core_zwave_js to tarfile: [Errno 2] No such file or directory: '/data/addon_configs/core_zwave_js' (FileNotFoundError)
2025-05-09 10:50:47.852 ERROR (MainThread) [supervisor.backups.backup] Can't create backup for core_zwave_js
2025-05-09 10:50:47.852 WARNING (MainThread) [supervisor.backups.backup] Can't save Add-on core_zwave_js: Can't create backup for core_zwave_js