Use native JSON in Elixir

[TylerWitt]

What are you trying to accomplish?

This bumps the Elixir version to 1.18 and the OTP version to 27.

It allows both

• This also lets us support depth for git repositories.
• Native JSON processing (no dependencies at all).

Anything you want to highlight for special attention from reviewers?

How will you know you've accomplished your goal?

Checklist

• I have run the complete test suite to ensure all tests and linters pass.
• I have thoroughly tested my code changes to ensure they work as expected, including adding additional tests for new functionality.
• I have written clear and descriptive commit messages.
• I have provided a detailed description of the changes in the pull request, including the problem it addresses, how it fixes the problem, and any relevant details about the implementation.
• I have ensured that the code is well-documented and easy to understand.

[abdulapopoola]

Thanks @TylerWitt , looking forward to your contribution!