Unbinds defined in editor will sometimes not work

[KoBeWi]

Godot version

4.0 c7ceb94

System information

Windows 10 x64

Issue description

I have a scene where I connected AnimationPlayer's animation_finished to node's queue_free using argument unbind. Here's how it should work:

Here's what actually happens:

The console is spammed with this error:

The unbinds are not working correctly.

This was caused by #67714
I originally detected this issue before the PR was merged and follow-up PRs did not fix it unfortunately.

Steps to reproduce

1. Connect AnimationPlayer's animation_finished to queue_free
   
2. Run the scene
3. The node will be freed correctly. Did I mention that the issue can't be reproduced in minimal project so these steps are useless? .-.

Minimal reproduction project

Can't be reproduced in minimal project unfortunately.
I can provide a copy of my project for debugging purposes though.

[akien-mga]

CC @adamscott

[adamscott]

I'm on it.