Allow empty "info" key for repodata.json

[dahakawang]

Checklist

• I added a descriptive title
• I searched open reports and couldn't find a duplicate

What happened?

Hello, Rattler team! I've started to use pixi at work after trying it for some time at home, but within the context of our on-prem Artifactory, it always fails with the below error:

  × failed to parse repodata.json
  ╰─▶ missing field `subdir` at line 2 column 14

After digging into it for a bit I start to believe that this is because Artifactory emits a repodata.json with a slight schema difference that rattler is not comfortable with:

{
  "info" : { },    <--- for whatever reason, this is empty but still presented
  "packages" : {
  }
}

while it looks like in rattler, if "info" is presented, it would require "subdir" to be also there: https://github.com/conda/rattler/blob/main/crates/rattler_conda_types/src/repo_data/mod.rs#L74

I'm not sure what the spec says about this (or if there's a spec?), but to me it's unlikely to change Artifactory's behavior, plus both conda/mamba work in the same context. I thus want to turn to you guys for some help, would it be possible to model this on the rattler side in a way that such repodata.json is allowed?

Additional Context

No response

[baszalmstra]

Sure, Id be happy to accept a PR!