FindCUDAToolkit: Fix nvrtc_builtins library name

The lib is named `libnvrtc-builtins.so`, not `libnvrtc_builtins.so`.

Update the change from commit 2a94c762ed (FindCUDAToolkit: Add support
for CUDA::nvrtc_static, 2023-01-20, v3.26.0-rc1~55^2).  Apply a fix
similar to commit 9688a8ebc2 (FindCUDAToolkit: Fix
`nvrtc_builtins_static` library name, 2023-02-03, v3.26.0-rc2~15^2).