hidi validate can't load unix path but transform can?

[baywet]

Describe the bug
hidi validate -d /a/valid/unix/path.yaml will return
Could not validate the document, reason: Invalid URI: The Authority/Host could not be parsed.

yet hidi transform --cs /another/valid/path.csdl -o /some/other/path.yaml will work.

We should align how source files are loaded to get a consistent behaviour.

[MaggieKimani1]

@baywet please provide the absolute path you're validating in the metadata repo for me to reproduce this.

[baywet]

run is here https://github.com/microsoftgraph/msgraph-metadata/actions/runs/4019312471/jobs/6905992113
path being passed was something like this /home/runner/work/msgraph-metadata/msgraph-metadata/openapi/v1.0/openapi.yaml