chore(amplify-alpha): add dependency from @aws-cdk/custom-resource-ha…

…ndlers (aws#28373)

Add dependency from from **@aws-cdk/custom-resource-handlers** to **@aws-cdk/aws-amplify-alpha** as part of effort to standardize custom resource creation and bundling of source code.


Verified addition with `yarn install` and `yarn test`. 


Closes aws#28289.

----

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

packages/@aws-cdk/aws-amplify-alpha/package.json

@@ -86,6 +86,7 @@
     "@aws-cdk/cdk-build-tools": "0.0.0",
     "@aws-cdk/integ-runner": "0.0.0",
     "@aws-cdk/pkglint": "0.0.0",
+    "@aws-cdk/custom-resource-handlers": "0.0.0",
     "@aws-sdk/client-amplify": "3.451.0",
     "@aws-sdk/client-s3": "3.451.0",
     "@aws-sdk/s3-request-presigner": "3.451.0",