terraform GCP cloud function without having to deploy via terraform in CI or breaking past deployments when running locally?

I have some working terraform definitions among a larger project:

resource "google_storage_bucket" "owlee_functions_bucket" {
  name     = "owlee_functions_bucket"
  location = "europe-west2"
  project  = "owlee-software"
}

resource "google_storage_bucket_object" "archive" {
  name   = "index.zip"
  bucket = google_storage_bucket.owlee_functions_bucket.name
  source = "../apps/backend/dist/index.zip"
}

resource "google_cloudfunctions_function" "backend_function" {
  name    = "backend_function"
  runtime = "nodejs16"
  project = "owlee-software"
  region  = "europe-west2"

  available_memory_mb   = 128
  source_archive_bucket = google_storage_bucket.owlee_functions_bucket.name
  source_archive_object = google_storage_bucket_object.archive.name
  trigger_http          = true
  entry_point           = "OWLEE"
}

Then I'm trying to deploy via CI, for now, I'm just running terraform apply after zipping up the new version of the function to handle deployment.

It's not great and I'd like to change that to a non-terraform process ideally but that doesn't seem to be documented/possible anywhere which makes me think I have the wrong approach with this.

The second issue which is more urgent to solve --

I want to continue managing my infrastructure locally for now and do not want to have to zip up a new version of the function to deploy everytime I have to run terraform apply locally.

Is there a way -- after its creation -- to avoid overwriting/uploading the function via terraform?

I'm guessing this would be somewhat necessary for the CI deployment to work anyway.

I've looked at a handful of other SO threads but they were looking at specifics around cloud-build and the artifacts registry.