Here is the latest Ryzen 5600G AMD Driver from 01/23/2024: https://www.amd.com/en/support/apu/amd-ryzen-processors/amd-ryzen-5-5000-g-series-desktop-processors...
First delete the created AMD Installation folder at C:\AMD and then download and run DDU with the internet disconnected unless you already have Windows Driver Update disabled.
After DDU reboots install the full latest AMD package you downloaded from AMD download page.
Afterwards run GPU-Z again and see if OpenCL is finally enabled for your IGPU again.
I helped this User with a 7600XT that had the exact same issue you are having with your IGPU: https://community.amd.com/t5/drivers-software/no-opencl-on-rx-7700-xt/m-p/655397#M186119
The User found a fix (Solution) in the thread that you might want to try and see if his fix also fixes your Opencl issue. Click on his link in the SOLUTION reply: