[`cuda kernels`] only compile them when initializing (#29133)
* only compile when needed
* fix mra as well
* fix yoso as well
* update
* rempve comment
* Update src/transformers/models/deformable_detr/modeling_deformable_detr.py
* Update src/transformers/models/deformable_detr/modeling_deformable_detr.py
* opps
* Update src/transformers/models/deta/modeling_deta.py
* nit