Fix resourceGithubDependabotOrganizationSecretCreateOrUpdate

[frankywahl]

Fixes a regression used when trying to create/update a dependabot organization secret. List is an int so cannot be cast to a different type. We therefore double convert it.

There was a regression introduced by version 5.27. This happened as the go-github client moved over to using int64 as ids in v53.0.0

terraform {
  required_providers {
    github = {
      source = "integrations/github"
      version = "5.27.0"
    }
  }
}

provider "github" {
  owner = var.owner
}

variable "owner" {
  type = string
}

resource "github_repository" "example" {
  name        = "example"
  description = "My awesome codebase"
  visibility = "public"
}

resource "github_dependabot_organization_secret" "example" {
  secret_name     = "example"
  visibility      = "selected"
  plaintext_value = "anything"
  selected_repository_ids = [
    github_repository.example.repo_id,
  ]
}

Resolves #1746

Pull request checklist

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
• Added the appropriate label for the given change

Does this introduce a breaking change?

It should fix an issue after the provider get upgraded.

• No

Notes:

• Unsure how to write a test for this change. Guidance would be nice. I ran an integration test and it all worked using the sample code and a local build of the provider pointing the client that had the change.
• Depends on Fix CreateOrUpdateOrgSecret regression introduced in v53 google/go-github#2817 being released (and client updated)

[kfcampbell]

Thank you!