Feature request: Metrics - environment variable to allow customer disable custom metrics

[hjgraca]

Use case

Original discussion: aws-powertools/powertools-lambda-python#2986

Similar to the Tracer utility (https://docs.powertools.aws.dev/lambda/python/latest/core/tracer/#environment-variables), our customers want to disable custom metrics in environments like dev and others.

More information here: https://discord.com/channels/1006478942305263677/1006478942787604491/1143575948994826260

Solution/User Experience

Create an environment variable to explicitly disable custom metrics.

Alternative solutions

Acknowledgment

• This feature request meets Powertools for AWS Lambda (.NET) Tenets
• Should this be considered in other Powertools for AWS Lambda languages? i.e. Python, Java, and TypeScript