Google_cloudbuildv2_connection and google_cloudbuildv2_repository - any way to get it to access public repositories?

I’ve got the Google Cloud Build app installed in the account, and I can set up a connection and link a repository that I own, but is there any way to make a GCP repository that is linked against a public repo that I do not own? When I tried the following block:

resource "google_cloudbuildv2_repository" "python-docs-samples" {
  project           = local.gcp_project
  location          = local.gcp_region
  name              = "python-docs-samples"
  parent_connection =
  remote_uri        = ""

I get:

│ Error: Error creating Repository: operation received error: error code "9", message: repository GoogleCloudPlatform/python-docs-samples does not exist or is not accessible to the Cloud Build GitHub App (installation ID 45355168), details: []
│  details: map[]

I have a similar block with a private repo I own that works fine.