[BUG]: Dead symlinks in repository

### Is this a duplicate?

- [X] I confirmed there appear to be no [duplicate issues](https://github.com/NVIDIA/cccl/issues) for this bug and that I agree to the [Code of Conduct](CODE_OF_CONDUCT.md)

### Type of Bug

Something else

### Component

libcu++

### Describe the bug

There are currently dead symlinks [in the libcudacxx subdirectory](https://github.com/NVIDIA/cccl/tree/main/libcudacxx) for the changelog, code of conduct, and readme. I assume that these point to old docs pages that were moved as part of the CCCL unification.

### How to Reproduce

N/A

### Expected behavior

The symlinks should either be fixed to point to the correct locations or removed.

### Reproduction link

_No response_

### Operating System

_No response_

### nvidia-smi output

_No response_

### NVCC version

_No response_