`burn-import` with only `safetensors` feat fails to build

[swfsql]

Describe the bug
Depending on burn-import with only the safetensors feature fails to build.

To Reproduce
A blank project with a dependency:

[dependencies.burn-import]
# version = "0.18.0"
git = "https://github.com/tracel-ai/burn.git"
# 2025-05-16 main
rev = "63c652845ce945a89e6c88aee66dad3c797f5b02"
default-features = false
features = ["safetensors"]

Fails to build with:

error: cannot find derive macro `new` in this scope
  --> /usr/local/cargo/git/checkouts/burn-6c277d792b0d5d7a/63c6528/crates/burn-import/src/safetensors/recorder.rs:17:10
   |
17 | #[derive(new, Debug, Default, Clone)]
   |          ^^^
   |
help: consider importing this derive macro
   |
1  + use derive_new::new;
   |

error: could not compile `burn-import` (lib) due to 1 previous error

Expected behavior
Successful build.