Bump github.com/aws/aws-sdk-go-v2/config from 1.27.35 to 1.28.7 in /scripts/internal/get-testing-ci-user-creds

Bump github.com/aws/aws-sdk-go-v2/config from 1.27.35 to 1.28.7 in /scripts/internal/get-testing-ci-user-creds #13642