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/mod.rs

@@ -0,0 +1,30 @@
+// #[allow(unused_imports)] // required for re-included modules
+pub use super::*;
+
+mod avg_pool2d;
+mod bernoulli;
+mod cast;
+mod cat;
+mod clamp;
+mod contiguous;
+mod conv2d;
+mod conv3d;
+mod conv_transpose2d;
+mod conv_transpose3d;
+mod cross;
+mod gather;
+mod mask_fill;
+mod mask_where;
+mod max_pool2d;
+mod max_pool2d_backward;
+mod normal;
+mod quantization;
+mod reduce;
+mod repeat_dim;
+mod scatter;
+mod select;
+mod select_assign;
+mod slice;
+mod slice_assign;
+mod unary;
+mod uniform;