Incremental builds don't work with --remote-build

**Describe the Issue:**

```
$ doctl serverless deploy . --remote-build --incremental
Deploying '/Users/nathan/project'
to namespace 'fn-...'
on host 'https://faas-syd1-c274eac6.doserverless.co'
Error: Cannot read properties of undefined (reading 'packageVersions')
```

**Environment:**

- doctl version: doctl version 1.104.0-release
- OS: macOS Sonoma
- Installation method: Github release

**Additional Details:**

I'm not sure if incremental builds are supposed to work with remote builds, but that would save a lot of time, especially when deploying functions across multiple regions.