Generated swift model for a hasOne relation uses incorrect arguments

### Environment information

```plain text
System:
OS: macOS 15.0
CPU: (8) arm64 Apple M2
Memory: 129.42 MB / 24.00 GB
Shell: /bin/zsh
Binaries:
Node: 22.9.0 - /opt/homebrew/bin/node
Yarn: undefined - undefined
npm: 10.8.3 - /opt/homebrew/bin/npm
pnpm: undefined - undefined
NPM Packages:
@aws-amplify/auth-construct: 1.3.1
@aws-amplify/backend: 1.3.0
@aws-amplify/backend-auth: 1.2.0
@aws-amplify/backend-cli: 1.2.8
@aws-amplify/backend-data: 1.1.4
@aws-amplify/backend-deployer: 1.1.3
@aws-amplify/backend-function: 1.5.0
@aws-amplify/backend-output-schemas: 1.2.0
@aws-amplify/backend-output-storage: 1.1.2
@aws-amplify/backend-secret: 1.1.2
@aws-amplify/backend-storage: 1.2.0
@aws-amplify/cli-core: 1.1.3
@aws-amplify/client-config: 1.3.1
@aws-amplify/deployed-backend-client: 1.4.1
@aws-amplify/form-generator: 1.0.3
@aws-amplify/model-generator: 1.0.8
@aws-amplify/platform-core: 1.1.0
@aws-amplify/plugin-types: 1.3.0
@aws-amplify/sandbox: 1.2.2
@aws-amplify/schema-generator: 1.2.4
aws-amplify: 6.6.2
aws-cdk: 2.159.1
aws-cdk-lib: 2.159.1
typescript: 5.6.2
AWS environment variables:
AWS_STS_REGIONAL_ENDPOINTS = regional
AWS_NODEJS_CONNECTION_REUSE_ENABLED = 1
AWS_SDK_LOAD_CONFIG = 1
No CDK environment variables
```

### Codegen packages

```plain text
kanaiamplify@1.0.0 /Users/concaveusr/Projects/KanaiAmplify
└─┬ @aws-amplify/backend-cli@1.2.8
└─┬ @aws-amplify/model-generator@1.0.8
└── @aws-amplify/graphql-generator@0.4.5
```

### Description

hasOne relations generate incorrect Swift code.

If I define a hasOne model like this:

```
const schema = a.schema({
Cart: a.model({
customerId: a.id(),
customer: a.belongsTo('Customer', 'customerId'),
}),
Customer: a.model({
activeCart: a.hasOne('Cart', 'customerId')
}),
});
```

Then the Swift generated code has a line like

```
model.fields(
...
.hasOne(customer.activeCart, is: .optional, ofType: Cart.self, associatedFields: [Cart.customerId])
...
)
```

This throws the following errors:

```
Argument type '[Cart.CodingKeys]' does not conform to expected type 'CodingKey'
Incorrect argument label in call (have '_:is:ofType:associatedFields:', expected '_:is:ofType:associatedWith:')
```

I can silence these errors by using the correct function label `associatedWith` and by removing the square brackets:

```
.hasOne(customer.activeCart, is: .optional, ofType: Cart.self, associatedWith: Cart.customerId)
```