feat: Deprecate node 12

[astuyve]

What does this PR do?

Closes #71

Testing Guidelines

Additional Notes

Types of changes

• Bug fix
• New feature
• Breaking change
• Misc (docs, refactoring, dependency upgrade, etc.)

Check all that apply

• This PR's description is comprehensive
• This PR contains breaking changes that are documented in the description
• This PR introduces new APIs or parameters that are documented and unlikely to change in the foreseeable future
• This PR impacts documentation, and it has been updated (or a ticket has been logged)
• This PR's changes are covered by the automated tests
• This PR collects user input/sensitive content into Datadog

[astuyve]

Verified this via creating a macro lambda stack from a this branch:

And instrumenting a SAM app (logs from the macro function running when deploying the SAM app):

and checking the layer/extension was correctly applied, the handler didn't error, and telemetry was passed to datadog.