Downtime objects are not removed properly when parent owner is modified

[RincewindsHat]

Describe the bug

Downtime objects are not removed properly when the owner still exists although the Downtime itself is obsolete.

The error in the log looks like this:

2024-10-18 16:29:42 +0200] critical/ScheduledDowntime: Exception occurred during removal of obsolete downtime for scheduled downtime 'network/switch/h3c-comware-lsq1wcmd0!test': Error: Cannot remove downtime 'network/switch/h3c-comware-lsq1wcmd0!4b5e20c6-fb95-40f0-829a-300ac8678bb0'. It is owned by scheduled downtime object 'network/switch/h3c-comware-lsq1wcmd0!test'

To Reproduce

1. Create a ScheduledDowntime
2. Deploy/reload the configuration
3. Modify the ScheduledDowntime but do NOT change the name
4. Deploy/reload the configuration

Expected behavior

The "old" `Downtime object should be properly deleted.

Your Environment

Include as many relevant details about the environment you experienced the problem in

• Version used (icinga2 --version): icinga2 - The Icinga 2 network monitoring daemon (version: r2.14.2-1)

[yhabteab]

Duplicate of #10042

[RincewindsHat]

Sorry, didn't search for closed issues/PRs