Compiling typescript resolver with esBuild throws `Unexpected token 'export'` on import '@aws-appsync/utils/dynamodb';

Hi,

As directed in the docs (https://docs.aws.amazon.com/appsync/latest/devguide/resolver-reference-overview-js.html#migrating-resolvers) I am using the Dynamodb module:
```
import * as ddb from '@aws-appsync/utils/dynamodb';
```
but when I build my TS to JS I am getting an error from my esbuild:

```
export * from './lib/dynamodb-helpers';
^^^^^^

SyntaxError: Unexpected token 'export'
at internalCompileFunction (node:internal/vm:73:18)
at wrapSafe (node:internal/modules/cjs/loader:1178:20)
at Module._compile (node:internal/modules/cjs/loader:1220:27)
at Module._extensions..js (node:internal/modules/cjs/loader:1310:10)
at Object.require.extensions. [as .js] (/Users/mattijs/www/respark/apollo/apollo-client-api/node_modules/ts-node/src/index.ts:1608:43)
```

I am building my ts as follows:
```
const result = esbuild.buildSync({
stdin: {
contents: file,
loader: 'ts',
},
external: ['@aws-appsync/utils'],
bundle: true,
write: false,
platform: 'node',
target: 'esnext',
format: 'esm',
sourcemap: 'inline',
sourcesContent: false,
});
```
I tried adding the `'@aws-appsync/utils/dynamodb'` to externals but to no avail.

How do I resolve this issue?

Start with the reported esbuild.buildSync configuration and the import of @aws-appsync/utils/dynamodb, then reproduce the Unexpected token 'export' error using the command setup described in the issue. Done means the TypeScript resolver compiles successfully without that syntax error while retaining the documented DynamoDB import.

Written by the indexing model from the issue text.