chore(bedrock): support Pixtral Large 25.02 (#34084)

Ref
* https://aws.amazon.com/about-aws/whats-new/2025/04/amazon-bedrock-pixtral-large-25-02-mistral-ai/
* https://docs.aws.amazon.com/bedrock/latest/userguide/models-supported.html


### 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*

Author: mazyu36

Diff for: packages/aws-cdk-lib/aws-bedrock/lib/foundation-model.ts

@@ -392,6 +392,9 @@ export class FoundationModelIdentifier {
   /** Base model "mistral.mistral-large-2407-v1:0". */
   public static readonly MISTRAL_LARGE_2_V0_1 = new FoundationModelIdentifier('mistral.mistral-large-2407-v1:0');
 
+  /** Base model "mistral.pixtral-large-2502-v1:0". */
+  public static readonly MISTRAL_PIXTRAL_LARGE_2502_V1_0 = new FoundationModelIdentifier('mistral.pixtral-large-2502-v1:0');
+
   /**
    * Base model "stability.stable-diffusion-xl".
    * @deprecated use latest version of the model