feat: update workspace paths and enhance gitignore

- Updated stablediffusion crate path from "../stable-diffusion-burn" to "./crates/stable-diffusion-burn" for proper workspace resolution
- Enhanced .gitignore to include generated model files (.mpk, .pt, .bin, .safetensors, .ckpt) and user_data directory
- Added Cargo.lock to gitignore with appropriate comment
- Reorganized IDE files section in gitignore for better clarity
- Added newline at end of file for proper formatting

crates/stable-diffusion-burn/burn-crates/burn-backend-tests/tests/cubecl/slice.rs

@@ -0,0 +1,19 @@
+use super::*;
+use burn_tensor::Tolerance;
+use burn_tensor::{Distribution, Tensor};
+
+#[test]
+fn slice_should_work_with_multiple_workgroups() {
+    let tensor =
+        Tensor::<TestBackend, 2>::random([6, 256], Distribution::Default, &Default::default());
+    let indices = [3..5, 45..256];
+    let tensor_ref =
+        Tensor::<ReferenceBackend, 2>::from_data(tensor.to_data(), &Default::default());
+
+    let actual = tensor.slice(indices.clone());
+    let expected = tensor_ref.slice(indices);
+
+    expected
+        .into_data()
+        .assert_approx_eq::<FloatElem>(&actual.into_data(), Tolerance::default());
+}