fix: revert readyToUse in health endpoint

[0xJuancito]

Description

The recently added readyToUse attribute in #927 breaks the current kernel implementation, as it is expecting all the attributes from the object returned by the health endpoint to be Healthy: https://github.com/decentraland/kernel/blob/afd06bd9837cb355b3ef62bde4fce77e0e02aa9e/packages/shared/dao/index.ts#L90-L97

Reverting this until a change is made on the kernel repository

Fix #933

Changes

Specify the behavior changes introduced by this pull request

• Remove readyToUse in lambdas health endpoint

Types of changes

What types of changes does your code introduce? Put an x in all the boxes that apply:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change). If there's an API change, link the pull request in the API spec repository and the accepted DAO governance poll
• I have read the CONTRIBUTING document.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.