I know that this issue has been solved but for further possible help to others, I encountered exactly the same issue today and it turned out to be because the package file was truncated when downloaded from the official repository. The only way I could get around it was by going to Arch Linux - intel-oneapi-basekit 2024.1.0.596-3 (x86_64) and then selecting the ‘download from mirror’ option to get a local copy which I then installed using the pamac using the ‘install local package’ option. The file that downloaded via pamac was about 550mb but the actual file was something like 2.3gb.
Hope that helps someone.