chore: Disable return constant error

[kevaundray]

Description

Currently this breaks contracts in aztec and the private kernel circuit. Although its likely a logic problem in those circuits, since we don't generate enough information to actually debug them right now (just the line) -- Its better to disable it until it becomes a warning and then work on improving the diagnostic so that users can figure out why there is a constant being returned as a public input.

Problem*

Resolves

Summary*

Documentation

• This PR requires documentation updates when merged.

  • I will submit a noir-lang/docs PR.
  • I will request for and support Dev Rel's help in documenting this PR.

Additional Context

PR Checklist*

• I have tested the changes locally.
• I have formatted the changes with Prettier and/or cargo fmt on default settings.

[kevaundray]

@guipublic tagging you, feel free to tag the issue when you create it about making this into a warning

[guipublic]

you also need to de-activate the test case