chore(ec2): add missing interface VPC endpoint (#31907)

### Issue # (if applicable)

N/A

### Reason for this change

The `InterfaceVpcEndpointAwsService` class was missing the AWS Price List service.

### Description of changes

Added `InterfaceVpcEndpointAwsService.PRICING_API` to the enum, connected to the service `'pricing.api'` in accordance with [documentation](https://docs.aws.amazon.com/vpc/latest/privatelink/aws-services-privatelink-support.html).

### Description of how you validated changes

Verified the extension via the documentation, and confirmed the endpoint exists in the console: 
![image](https://github.com/user-attachments/assets/4a85b146-fd97-4ec7-94a0-0f7d6551e6f1)

### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

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*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/aws-cdk-lib/aws-ec2/lib/vpc-endpoint.ts

@@ -517,6 +517,7 @@ export class InterfaceVpcEndpointAwsService implements IInterfaceVpcEndpointServ
   public static readonly PIPES_FIPS = new InterfaceVpcEndpointAwsService('pipes-fips');
   public static readonly PRICE_LIST = new InterfaceVpcEndpointAwsService('pricing.api');
   public static readonly POLLY = new InterfaceVpcEndpointAwsService('polly');
+  public static readonly PRICING_API = new InterfaceVpcEndpointAwsService('pricing.api');
   public static readonly PRIVATE_5G = new InterfaceVpcEndpointAwsService('private-networks');
   public static readonly PRIVATE_CERTIFICATE_AUTHORITY = new InterfaceVpcEndpointAwsService('acm-pca');
   public static readonly PRIVATE_CERTIFICATE_AUTHORITY_CONNECTOR_AD = new InterfaceVpcEndpointAwsService('pca-connector-ad');