Texture Filtering Default Inconsistency

## Bevy version: 0.12.0
## Relevant system information:
CPU: Ryzen 9 7950X
GPU: Radeon RX 7900 XTX
Memory: 32 GB DDR5

If your bug is rendering-related, copy the adapter info that appears when you run Bevy:
`AdapterInfo { name: "AMD Radeon RX 7900 XTX", vendor: 4098, device: 29772, device_type: DiscreteGpu, driver: "AMD proprietary driver", driver_info: "23.9.3 (LLPC)", backend: Vulkan }

## What you did
Spawned a PbrBundle. When loading a texture with assets.load(), texture filtering mode appears to default to bevy::render::texture::ImageFilterMode::Linear (Intended behavior, based on [0.7 to 0.8 migration guide](https://bevyengine.org/learn/migration-guides/0.7-0.8/)):
```
PbrBundle {
mesh: match part {
&Part::Wire => assets.load("models/parts/wire16.obj"),
},
material: materials.add(StandardMaterial {
base_color_texture: Some(assets.load(
"models/parts/materials/wire16.png",
// |settings| {
// *settings = ImageLoaderSettings {
// sampler: bevy::render::texture::ImageSampler::Descriptor(
// ImageSamplerDescriptor {
// //mag_filter: bevy::render::texture::ImageFilterMode::Nearest,
// //min_filter: bevy::render::texture::ImageFilterMode::Nearest,
// //mipmap_filter: bevy::render::texture::ImageFilterMode::Nearest,
// ..default()
// },
// ),
// ..default()
// };
// },
)),
..default()
}),
..default()
},
```

When loading a texture with assets.load_with_settings() (WITHOUT CHANGING SETTINGS), texture filtering mode appears to default to bevy::render::texture::ImageFilterMode::Nearest (UNINTENDED behavior, based on [0.7 to 0.8 migration guide](https://bevyengine.org/learn/migration-guides/0.7-0.8/)
```
PbrBundle {
mesh: match part {
&Part::Wire => assets.load("models/parts/wire16.obj"),
},
material: materials.add(StandardMaterial {
base_color_texture: Some(assets.load_with_settings(
"models/parts/materials/wire16.png",
|settings| {
*settings = ImageLoaderSettings {
sampler: bevy::render::texture::ImageSampler::Descriptor(
ImageSamplerDescriptor {
//mag_filter: bevy::render::texture::ImageFilterMode::Nearest,
//min_filter: bevy::render::texture::ImageFilterMode::Nearest,
//mipmap_filter: bevy::render::texture::ImageFilterMode::Nearest,
..default()
},
),
..default()
};
},
)),
..default()
}),
..default()
},
))

```

Start by tracing the texture-loading paths through assets.load() and assets.load_with_settings(), focusing on ImageLoaderSettings, ImageSampler, and ImageSamplerDescriptor. Compare the sampler defaults produced by both calls against the 0.7-to-0.8 migration guide. Done means both loading APIs use the same intended default filtering behavior, with coverage for the inconsistency.

Written by the indexing model from the issue text.