(CustomResources): Error: Resolution error: Resolution error: Trying to resolve() a Construct at /Resources/${Token[

### Describe the bug

When attempting to synthesize a custom resource that creates resources in Salesforce, I get the following error

### Expected Behavior

I was expecting to see SalesforceObject and SalesforceObjectFields as properties of "Custom::SalesforceMetadata" in the synthesized template

```json

"salesforcemetadataSalesforceMetadataResourceFCFF42F2": {
"Type": "Custom::SalesforceMetadata",
"Properties": {
"ServiceToken": {
"Fn::GetAtt": [
"salesforcemetadataSalesforceProviderframeworkonEventD0B8B143",
"Arn"
]
}

// SalesforceObject
// SalesforceObject.SalesforceObjectField

},
"UpdateReplacePolicy": "Delete",
"DeletionPolicy": "Delete",
"Metadata": {
"aws:cdk:path": "cdk-salesforce-iac-poc-stack/salesforce-metadata/SalesforceMetadataResource/Default"
}
},
```

### Current Behavior

`cdk synth` doesn't finish and throws the folllowing error

### Reproduction Steps

Run `cdk synth` in this repo

https://github.com/AllanOricil/cdk-salesforce-iac-poc

### Possible Solution

_No response_

### Additional Information/Context

_No response_

### CDK CLI Version

2.141.0

### Framework Version

_No response_

### Node.js Version

18.19.1

### OS

macos latest

### Language

TypeScript

### Language Version

5.4.5

### Other information

My goal with this custom construct it to be able to use a single tool to develop solutions that require both Salesforce and AWS resources. This simplest repository I shared is attempting to create a very simple Database Table in Salesforce (they call it SObject, but let's try to use terms which both of us understand even if it is wrong). I want to join all salesforce resources under one called "SalesforceMetadata" so that it represents all metadata that belongs to a single Salesforce Organization. Moreover, I did not create custom resources for SalesforceObject and SalesforceObjectField constructs because I wan't them to be deployed by Custom::SalesforceMetadata. In other words, they can't be deployed alone.

I want to build something like Mongodb Atlas did

https://github.com/mongodb/awscdk-resources-mongodbatlas

Clone the linked cdk-salesforce-iac-poc repository and first run `cdk synth` with the reported CDK CLI and Node.js versions. Inspect how SalesforceMetadata, SalesforceObject, and SalesforceObjectField are defined and compare the failure with the expected synthesized Custom::SalesforceMetadata properties. Done means synthesis completes and the expected Salesforce properties appear in the template.

Written by the indexing model from the issue text.