Could not insert a bundle (of type `bevy_a11y::AccessibilityNode`)

## Bevy version

0.11.2

## \[Optional\] Relevant system information

* Arch Linux
* `cargo 1.72.0 (103a7ff2e 2023-08-15)`
* `AdapterInfo { name: "AMD Radeon RX 6700 XT (RADV NAVI22)", vendor: 4098, device: 29663, device_type: DiscreteGpu, driver: "radv", driver_info: "Mesa 23.1.7-arch1.1", backend: Vulkan }`

## What you did

I was viciously clicking a UI button.

## What went wrong

Unexpected panic:

```
thread 'main' panicked at 'error[B0003]: Could not insert a bundle (of type `bevy_a11y::AccessibilityNode`) for entity 105v6 because it doesn't exist in this World.', /home/indy/.cargo/registry/src/index.crates.io-6f17d22bba15001f/bevy_ecs-0.11.2/src/system/commands/mod.rs:957:13
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Encountered a panic when applying buffers for system `bevy_ui::accessibility::button_changed`!
Encountered a panic in system `bevy_app::main_schedule::Main::run_main`!
```

Start with the reported `bevy_ui::accessibility::button_changed` system and the panic location in `bevy_ecs-0.11.2/src/system/commands/mod.rs:957`. Reproduce the failure by rapidly clicking a UI button under the reported Bevy version and inspect the three existing comments for context. Done means the scenario no longer panics when the accessibility command targets an entity that no longer exists.

Written by the indexing model from the issue text.