Add json as an optional dependency for ABC.Interpreter.JavaScript

What does this MR do?

This was previously not caught by the compilation test but will be necessary once nitrile!117 (merged) lands.

Changes to public APIs

None.

Author's checklist (required)

• If bugs have been solved, tests have been added (guidelines)
• A changelog entry has been added (guidelines)
• Newly added code is documented (guidelines)
• Newly added code has a style consistent with the rest of the repository
• Intermediate commits compile (use git rebase -i main if not)

Related issues