Provide constant for layer versions

[doblinger-extron]

Expected Behavior

I would like to be able to set the nodeLayerVersion to a constant value provided by this library so that I don't have to update this version on a constant basis. The Datadog serverless plugin seems to handle this with a map file:

https://github.com/DataDog/serverless-plugin-datadog/blob/main/src/layers.json

Example

const datadogLambda = new DatadogLambda(this, 'DatadogLambda', {
      flushMetricsToLogs: true,
      addLayers: true,
      nodeLayerVersion: NodeLayerVersion.UsEast1.Node22.Latest, // Ideally a constant for the latest layer version is available. Perhaps the region must also be taken into account
    });

Actual Behavior

const datadogLambda = new DatadogLambda(this, 'DatadogLambda', {
      flushMetricsToLogs: true,
      addLayers: true,
      nodeLayerVersion: 124 // the version is hardcoded and must be looked up from https://github.com/DataDog/datadog-lambda-js/releases
    });

[lym953]

Thanks for bringing this up! We do have a long-term plan to implement the Serverless Plugin approach across all the tools, including datadog-cdk-constructs, datadog-cloudformation-macro, terraform-aws-lambda-datadog and datadog-ci. However, it's not yet prioritized in the near future. If anyone else feels this pain, please comment or react on this issue so we can better prioritize it.