Prepare for v3.7.0 release

[austinvalle]

Follow-up to #649 and #650

This PR should be reflective of a normal preparation for a provider release, just need to run changie batch 3.7.0 && changie merge since all changelogs are ready to go in main

[austinvalle]

Follow-up from #650, since this PR is the second release through CRT

Alpha release was successfully promoted through CRT:

• https://github.com/hashicorp/crt-workflows-common/actions/runs/13508429147/job/37743440746

Some other confirmed checks:

• Pre-release GH tag created: https://github.com/hashicorp/terraform-provider-random/releases/tag/v3.7.0-alpha1
• Provider binary in releases.hashicorp.com
• Registry is synced: https://registry.terraform.io/providers/hashicorp/random/3.7.0-alpha1/docs/ephemeral-resources/password

I ran a local terraform init and then terraform validate on the following config:

terraform {
  required_providers {
    random = {
      source  = "hashicorp/random"
      version = "3.7.0-alpha1"
    }
  }
}

ephemeral "random_password" "example" {
  length = 10
}