Preview launch of AWS API Gateway and Azure API Management plugins

## Feature Feature **Preview launch of AWS API Gateway and Azure API Management plugins** API hub now includes two new built-in plugins for ingesting API metadata from third-party gateways: **AWS API Gateway** and **Azure API Management**. Both plugins are in [Public Preview](https://cloud.google.com/products#product-launch-stages), extending API hub's multi-cloud governance to give you a single pane of glass across your Google Cloud, AWS, and Azure APIs. **What's new** * **Automated discovery and onboarding**: Connect your AWS account or Azure API Management (APIM) service and API hub automatically discovers your existing deployed APIs and related metadata. * **Scheduled pull sync**: A full metadata sync runs every 6 hours by default, with reconciliation (upserts and orphan deletes) to keep your catalog in sync with the source gateway. * **Optional near-real-time push sync**: Deploy a customer-managed AWS Lambda function (for AWS API Gateway) or Azure Function (for Azure API Management) to relay control-plane change events to API hub in near real time. For sample deployment code, see the [apigee-samples](https://github.com/GoogleCloudPlatform/apigee-samples/tree/main/apihub-plugins) repository. For more information, see [About plugins](https://cloud.google.com/apigee/docs/apihub/plugins), [Manage third-party plugins](https://cloud.google.com/apigee/docs/apihub/manage-third-party-plugins), and [Create a plugin instance](https://cloud.google.com/apigee/docs/apihub/create-plugin-instances). ## Feature Feature **Spec-to-deployment linkage and gateway revision tracking in API hub (GA)** API hub now provides a first-class, bidirectional link between API specifications, operations, and the deployments that serve them, together with native tracking of the underlying gateway revision. **What's new** * **Direct visibility between specs and deployments**: See exactly which API specification and operations are served by a specific deployment, and navigate from a spec to the deployments that serve it. * **Native gateway revision tracking**: Deployments now capture and display their underlying gateway revision (for example, an Apigee proxy revision) via the new `source_revision` field on the Deployment resource. * **More accurate operation resolution**: When multiple revisions expose overlapping operations (same method and path), API hub associates each operation with its specific specification instead of dropping duplicates. * **Multiple spec revisions per API**: API hub can store multiple revisions of the same spec for an API deployed across different environments.