Deployment guide using Terraform is not working - for 14 and 16

## Steps to reproduce

Follow the documentation to deploy charmed-postgresql using the terraform providers and they will break.

## Expected behavior

Deployment should just complete as expected

## Actual behavior

```
$ terraform plan -var "juju_model_name=my-model"
╷
│ Error: Missing required argument
│
│ on main.tf line 1, in resource "juju_application" "machine_postgresql":
│ 1: resource "juju_application" "machine_postgresql" {
│
│ The argument "model_uuid" is required, but no definition was found.
╵
╷
│ Error: Unsupported argument
│
│ on main.tf line 3, in resource "juju_application" "machine_postgresql":
│ 3: model = "my-model"
│
│ An argument named "model" is not expected here.
```

## Versions

Operating system:

```
$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 22.04.5 LTS
Release: 22.04
Codename: jammy
```

Juju CLI:

```
$ juju version
3.6.21-genericlinux-amd64
```

LXD:

```
$ lxd version
5.21.4 LTS
```

Start by following the Terraform deployment documentation and inspect the main.tf juju_application resource shown in the error. Compare the documented model argument with the provider's required model_uuid argument; done means terraform plan completes successfully for PostgreSQL 14 and 16.

Written by the indexing model from the issue text.