[llvm] [llvm-readelf] Update outdated URL (PR #120498)

[via llvm-commits]

wenzhoumei wrote:

Hi @jh7370, thanks for the response! Would you recommend that I leave it as is or point to the general link of the mailing list instead (https://groups.google.com/g/generic-abi).

Also I'm very new to this so I'm not sure why tests are failing and what to do in this scenario. Will merging my branch on the latest version fix it?

https://github.com/llvm/llvm-project/pull/120498