Change the default value for `target`

[nuragic]

Prerequisites

• [X] I have written a descriptive issue title
• [X] I have searched existing issues to ensure the feature has not already been requested

🚀 Feature Proposal

This proposal aims to make the API simpler to understand; it doesn't change the actual behaviour, in fact it wants to keep it.

The only difference is that instead of using the special value any I’m proposing to just use an empty value ('', undefined…) to achieve same thing.

Motivation

• we don't need to create a special value to disable the target check, we just leave it empty
• we simplify the validation of target so it would only accept valid SemVer identifiers

Example

N/A