`VERSION` file missing from WASI SDK 24

[SingleAccretion]

I downloaded wasi-sdk-24.0-x86_64-windows.tar.gz from the 24's release artifacts, and the VERSION file that was there in 22 is missing, which does not look right.

[abrown]

Some initial findings:

• the new CMake build (from Rewrite the build system with CMake #429) should be trying to build the VERSION file (here)
• it isn't, even for the released Linux artifacts (this is not just a Windows issue)
• when I build this locally using ci/build.sh, the VERSION file does actually appear in build/install
• but VERSION does not appear in build/dist so I think CI is not picking it with the upload-artifact artifact action (confirmed: it is not present in the downloaded dist-x86_64-linux.zip from GitHub actions)
• once we do fix the copying to build/dist, do we need to update ci/merge-artifacts.sh to make sure it gets merged into the final *.tar file? (Alternately, we could stuff VERSION into one of the component *.tars).

[alexcrichton]

Ah yes my mistake! Can confirm that VERSION is only in the install and not in the tarballs. I do believe that merge-artifacts.sh will need to be updated to copy it from one tarball to another. I can work on this when I get back next week if no one else solves it in the meantime.