Bump aws-sdk and aws-appsync

Removes [aws-sdk](https://github.com/aws/aws-sdk-js). It's no longer used after updating ancestor dependency [aws-appsync](https://github.com/awslabs/aws-mobile-appsync-sdk-js). These dependencies need to be updated together.


Removes `aws-sdk`

Updates `aws-appsync` from 3.0.4 to 4.1.9
- [Release notes](https://github.com/awslabs/aws-mobile-appsync-sdk-js/releases)
- [Commits](https://github.com/awslabs/aws-mobile-appsync-sdk-js/compare/[email protected]@4.1.9)

---
updated-dependencies:
- dependency-name: aws-sdk
  dependency-type: indirect
- dependency-name: aws-appsync
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]