fix Link 'label:assets' field type as list

[fmigneault]

Posting a STAC Item that contains label:assets as defined below results in a validation error since the str doesn't match the expected list (https://github.com/stac-extensions/label?tab=readme-ov-file#links-source-imagery).

{
  "links": [
        {
          "rel": "source",
          "href": "https://hirondelle.crim.ca/data/stac/EuroSAT/data/full/ds/images/remote_sensing/otherDatasets/sentinel_2/tif/Pasture/Pasture_1687.tif",
          "type": "image/tiff; application=geotiff",
          "title": "Raster Pasture_1687 with Pasture class",
          "ml-aoi:role": "label",
          "label:assets": [
            "labels",
            "raster"
          ]
        }
  ]
}

I've tested that the fix works as expected by running our https://github.com/crim-ca/stac-app (STAC-FastAPI) with this stac-pydantic patch applied.

[fmigneault]

@vincentsarago
Hi. It is possible to validate this fix and its inclusion into STAC-FastAPI/pgstac?
This is blocking us from migrating our app to latest definitions using the label extension.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 95.52%. Comparing base (a927d25) to head (e811d0d).
Report is 129 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #183      +/-   ##
==========================================
- Coverage   96.59%   95.52%   -1.07%     
==========================================
  Files          25       25              
  Lines         587      671      +84     
==========================================
+ Hits          567      641      +74     
- Misses         20       30      +10     

Flag	Coverage Δ
unittests	95.52% <100.00%> (-1.07%)	⬇️

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[vincentsarago]

🤔 well to be honest I believe we should just remove the label attribute and let extension be handled with validate_extensions

https://github.com/stac-utils/stac-pydantic?tab=readme-ov-file#extensions

[fmigneault]

Yes. That makes the most sense IMO as well.
Are all extensions validated automatically by STAC-FastAPI when POSTing a STAC Item?
I don't see explicit calls to validate_extensions in the code.

[vincentsarago]

I don't think they are validated but we could add an option. Can you open an issue in stac-fastapi?

[fmigneault]

Yes. I can look into adding that.

[fmigneault]

Feature ready: stac-utils/stac-fastapi-pgstac#269

Replacement for this PR: #184