crashes during assets import

hello,

I'm having an issue with the Godots (not an editor run from the app) app: when I download and then import an asset (no matter what type) for an already downloaded editor, it crashes with a
`/app/bin/godots: line 4: 3 Segmentation fault (core dumped) /app/bin/godots-bin "$@"`
message.

steps taken:
1. Allow writing access to the folders used for projects/assets/demos
3. open the Godots app
4. click to the Asset Library tab
5. choose an item to download, click Download
6. when a dialog window pops up suggesting where to save the downloaded files, choose the accessible folders, click Import
7. crash

Additional log

```

F: No installations directory in /etc/flatpak/installations.d. Skipping
F: Opening system flatpak installation at path /var/lib/flatpak
F: Opening user flatpak installation at path /home/alex/.local/share/flatpak
F: Opening user flatpak installation at path /home/alex/.local/share/flatpak
F: Opening system flatpak installation at path /var/lib/flatpak
F: Skipping parental controls check for app/io.github.MakovWait.Godots/x86_64/stable since parental controls are disabled globally
F: Opening user flatpak installation at path /home/alex/.local/share/flatpak
F: Opening system flatpak installation at path /var/lib/flatpak
F: /var/lib/flatpak/runtime/org.freedesktop.Sdk/x86_64/24.08/bb83ffaa617df37ae1bf931171a77becf2698ac5492d310a97313e0eb32c0372/files/lib32 does not exist
F: Cleaning up unused container id 3063340859
F: Cleaning up per-app-ID state for io.github.MakovWait.Godots
F: Allocated instance id 2746053289
F: Add defaults in dir /io/github/MakovWait/Godots/
F: Add locks in dir /io/github/MakovWait/Godots/
F: Allowing homedir access
F: Not sharing "/mnt/location" with sandbox: Unable to open path "/mnt/location": No such file or directory
F: Not sharing "/media/alex/alex" with sandbox: Unable to open path "/media/alex/alex": No such file or directory
F: Allowing wayland access
F: Allowing x11 access
F: Allowing pulseaudio access
F: Pulseaudio user configuration file '/home/alex/.config/pulse/client.conf': Error opening file /home/alex/.config/pulse/client.conf: No such file or directory
F: Running 'bwrap --args 41 -- xdg-dbus-proxy --args=43'
F: Running 'bwrap --args 41 -- godots'
Godot Engine v4.5.stable.official.876b29033 - https://godotengine.org
OpenGL API 3.3.0 NVIDIA 580.159.03 - Compatibility - Using Device: NVIDIA - NVIDIA GeForce RTX 3050 Laptop GPU

Run window mode
ERROR: Invalid new child index: 5.
at: move_child (scene/main/node.cpp:507)
ERROR: Condition "slot >= slot_max" is true. Returning: nullptr
at: get_instance (./core/object/object.h:1055)
ERROR: Condition "slot >= slot_max" is true. Returning: nullptr
at: get_instance (./core/object/object.h:1055)
ERROR: Condition "slot >= slot_max" is true. Returning: nullptr
at: get_instance (./core/object/object.h:1055)
ERROR: Condition "slot >= slot_max" is true. Returning: nullptr
at: get_instance (./core/object/object.h:1055)

```

Reproduce the crash in the Godots app by following the Asset Library download and import steps described in the issue, using the reported Godot 4.5 environment. Start with the accompanying log, especially the invalid child-index and instance errors; done means importing an asset no longer crashes the app.

Written by the indexing model from the issue text.