renovate-config/doNotUpdateUploadArtifactToV4.json

{
    "packageRules": [
        {
            "description": "Do not update Artifact Upload Action to v4",
            "matchPackageNames": [ "actions/upload-artifact" ],
            "matchCategories": [ "ci" ],
            "allowedVersions": "!/v3/"
        }
    ]
}