[Dev Container][CUDA]Fix linker path (#108766)
Building with CUDA in dev container leads to error: `cannot find -lcudart_static`. This is because the libraries are under a custom CUDA_HOME, and `ld` cannot find it.
Updating the `LDFLAGS` environment variable works.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/108766
Approved by: https://github.com/drisspg
