Manage AWS SDK(s) version with Dependabot (#39738)

Set up Dependabot to manage the AWS SDK version.

With the current reactive and manual process, our dependencies are often outdated. To release a bugfix to a dependency, we need to wait for the following stack release instead of merging it shortly after it's available from AWS.

See #39492 to learn more.

.github/dependabot.yml

@@ -36,6 +36,10 @@ updates:
       - dependency-name: github.com/elastic/toutoumomoma
       - dependency-name: github.com/elastic/ebpfevents
       # Team:Team:obs-ds-hosted-services, Team:obs-infraobs-integrations
+      # AWS SDK dependencies
+      - dependency-name: github.com/aws/aws-sdk-go-v2/*
+      - dependency-name: github.com/aws/aws-lambda-go/*
+      - dependency-name: github.com/aws/smithy-go/*
       # Azure SDK dependencies
       - dependency-name: github.com/Azure/azure-sdk-for-go/*
       - dependency-name: github.com/Azure/azure-event-hubs-go/*
@@ -45,6 +49,9 @@ updates:
       - dependency-name: cloud.google.com/go/*
     groups:
       # Cloud providers' SDK dependencies
+      aws-sdks:
+        patterns:
+          - "github.com/aws/aws-sdk-go-v2/*"
       azure-sdks:
         patterns:
           - "github.com/Azure/azure-*-go"