build-demo-ios failing on the release/1.0 branch

[GregoryComer]

Example failure: https://github.com/pytorch/executorch/actions/runs/18292695452/job/52083577054. Seems to be unrelated to the PR that it started failing on. It looks like an infra failure / flake, but it is failing consistently on subsequent PRs.

Error:

skipping cache due to an error: Failed to clone repository https://github.com/pytorch/executorch:
    Cloning into bare repository '/Users/runner/Library/Caches/org.swift.swiftpm/repositories/executorch-6834a7c1'...
    error: RPC failed; HTTP 400 curl 22 The requested URL returned error: 400
    fatal: expected 'packfile'

[GregoryComer]

Resolved with #14959.