[iod]

I think you have gotten to the crux of it, distro package maintainers seem to have not done a particularly good job in many distros when it comes to AMD, but that is hardly AMD's fault as they have done a fairly good job at running their own full binaries repo¹ for various package formats. I also would recommend therefore that you change to AMD's repo as it definitely contains the HIP runtime. It would appear that you just need to add https://repo.radeon.com/rocm/yum/rpm to your package manager for Fedora. For ROCm OpenCL, my only pointer is that you have to make sure that you are adding the dynamic library path, for example:

  $ env LD_LIBRARY_PATH=/opt/rocm-5.4.0/opencl/lib clinfo

I am pretty sure that you should be able to resolve both OpenCL and Blender+HIP support given your configuration details given so far and I hope you figure it out.

¹ https://repo.radeon.com/rocm