Artifact in sprite rendering

## Bevy version

0.15.0

## \[Optional\] Relevant system information
```ignore
`AdapterInfo { name: "AMD Radeon Graphics (RADV RENOIR)", vendor: 4098, device: 5686, device_type: IntegratedGpu, driver: "radv", driver_info: "Mesa 24.2.6", backend: Vulkan }`
```

## What you did

Example code, using this CC0 tilemap texture [Image](https://github.com/user-attachments/assets/8442c06e-7443-4190-b70b-eda7023269be)

```rust
use bevy::prelude::*;
use std::collections::HashMap;

fn main() {
App::new()
.add_plugins(DefaultPlugins.set(ImagePlugin::default_nearest()))
.add_systems(Startup, startup)
.run();
}

fn startup(
mut commands: Commands,
assets: ResMut,
mut texture_atlas_layouts: ResMut>,
) {
let texture_handle = assets.load_with_settings(
"kenney_tiny-dungeon/Tilemap/tilemap_packed.png",
|settings: &mut bevy::image::ImageLoaderSettings| {
// Use `nearest` image sampling to preserve the pixel art style.
settings.sampler = bevy::image::ImageSampler::nearest();
},
);
let texture_atlas_layout =
TextureAtlasLayout::from_grid(UVec2::new(16, 16), 12, 11, None, None);
let texture_atlas_layout = texture_atlas_layouts.add(texture_atlas_layout);
commands.spawn(Camera2d);

let mut out = HashMap::new();

{ // generation, not super important, it just is easier to see the bug with some variety
for x in -2..=2 {
for y in -2..=2 {
out.insert(IVec2::new(x, y), 48);
}
}

for y in -2..=2 {
out.insert(IVec2::new(-3, y), 13);
out.insert(IVec2::new(3, y), 15);
}

for x in -2..=2 {
out.insert(IVec2::new(x, -3), 26);
out.insert(IVec2::new(x, 3), 2);
}

out.insert(IVec2::new(-3, -3), 25);
out.insert(IVec2::new(3, -3), 27);
out.insert(IVec2::new(-3, 3), 1);
out.insert(IVec2::new(3, 3), 3);
}

for (place, kind) in out {
let mut s = Sprite::from_atlas_image(texture_handle.clone(), TextureAtlas {
layout: texture_atlas_layout.clone(),
index: kind,
});
s.custom_size = Some(Vec2::new(1.0, 1.0));

let scale = 6.0;
commands.spawn((
s,
Transform::from_scale(Vec2::splat(16.0 * scale).extend(1.0))
* Transform::from_translation(place.as_vec2().extend(0.0)),
));
}
}
```

## What went wrong

There is misalignment 
It seems the bottom-left triangle of each quad has incorrect texturing, seemingly the wrong UVs, leading to it not matching the neighbouring triangle, and also bleeding over the edge of the atlas by 1 pixel

## Additional information
Maybe its something to do with rounding?!

Start by running the provided reproduction with Bevy 0.15.0, the tilemap image, ImagePlugin::default_nearest(), Sprite::from_atlas_image(), and TextureAtlasLayout::from_grid(). Inspect the sprite atlas rendering path around the generated UVs and compare the bottom-left triangle with its neighboring triangle. Done means the reproduced atlas sprites are aligned without edge bleeding.

Written by the indexing model from the issue text.