Step Functions: Numeric placeholder breaks rendering

## Problem

We're using placeholder values in our ASL files which are filled in using Terraform's `templatefile` function. When opening these files in VSCode the editor is erroring with the message `Value expected asl(516)`.

This problem was raised previously https://github.com/aws/aws-toolkit-vscode/issues/1140 with a fix released in `1.11.0`

## Steps to reproduce the issue

Create a `test.asl.json` file and add the following content

```
{
"StartAt": "Test Choice",
"States": {
"Test Choice": {
"Type": "Choice",
"Choices": [
{
"Variable": "$.config.metrics.getPaidEvent.count",
"NumericGreaterThan": ${my_placeholder},
"Next": "Done"
}
],
"Default": "Done"
},
"Done": {
"Type": "Pass",
"End": true
}
}
}
```

Observe the `Value expected` error

## Expected behavior

Using a placeholder for a numeric value doesn't error and the step function renderer works as expected

## System details (run the `AWS: About Toolkit` command)

OS: Darwin x64 22.5.0
Visual Studio Code extension host: 1.79.2
AWS Toolkit: 1.80.0
node: 16.17.1
electron: 22.5.7

Reproduce the issue in VSCode using the supplied test.asl.json content and confirm the Value expected error. Trace the Step Functions parsing or rendering path involved, then verify that a numeric placeholder no longer errors and the renderer works as expected.

Written by the indexing model from the issue text.