### What
The vercel storage adapter returns a 500 internal server error when a
file is not found.
It's expected that it will return 404 when a file is not found.
### Why
The `head` function from vercel blob sdk does not return undefined when
a blob is not found, but throws an error as documented here:
https://vercel.com/docs/storage/vercel-blob/using-blob-sdk#head
### How
Check if exception thrown is of type BlobNotFoundError and return a 404
in that case.
### Testing
***Note***: I have not been able to test this inside payload itself as
I'm unable to build a package to test with. I have tested the
implementation outside. Is it possible to get a canary build so proper
testing with package can be done?
Fixes#10326
d68a1eaafb