HDR camera renders nothing in a standard multi-camera setup

## Bevy version

0.15.3 and 0.16.0-rc.5

## Relevant system information

```ignore
`AdapterInfo { name: "AMD Radeon RX 7900 XTX (RADV NAVI31)", vendor: 4098, device: 29772, device_type: DiscreteGpu, driver: "radv", driver_info: "Mesa 25.0.3", backend: Vulkan }`
```

## What you did

Copied the [first person view model example](https://bevyengine.org/examples/camera/first-person-view-model/) and gave the world model camera HDR

## What went wrong

The HDR-enabled camera renders nothing anymore.

Without HDR:


With HDR:


Note that only giving HDR to the view model results in the same thing. The only configurations that works are
- giving all cameras HDR, which runs into https://github.com/bevyengine/bevy/issues/18903 when using TAA, or
- setting the view model camera to the following

```rust
Camera {
hdr: true,
order: 1,
// this part is relevant
clear_color: ClearColorConfig::Custom(Color::NONE),
output_mode: CameraOutputMode::Write {
blend_state: Some(BlendState::ALPHA_BLENDING),
clear_color: ClearColorConfig::None,
},
..default()
},
```

## Additional information

Relevant older issue: https://github.com/bevyengine/bevy/issues/6754, but note that that issue is distinct. Enabling HDR on the split screen example does not cause an problem for me.