polywrap build command's default manifest is using an old manifest version

[pileks]

When running polywrap build without a polywrap.build.yaml manifest, the default build manifest used by the CLI is version 0.2 instead of 0.3, causing the following warning message to appear:

BuildManifest is using an older version of the manifest format (0.2.0). Please update your manifest to the latest version (0.3.0) by using the "polywrap manifest migrate <type>" command.

Solution: Update the default build manifest/manifests.