Disable signing for macro executables

[pepicrft]

Why is this needed?

Macro executables don't need signing and therefore we should disable it to prevent build issues like the following:

❌ error: An empty code signing identity is not valid when signing a binary for the 'Command-line Tool' product type. (in target 'MockableMacro' from project 'Mockable')

Steps to address the need

We can extend the logic in DefaultSettingsProvider to include the following build settings by default:

[
  "CODE_SIGN_IDENTITY": "",
  "PROVISIONING_PROFILE": "",
  "CODE_SIGNING_REQUIRED": "NO",
  "CODE_SIGNING_ALLOWED": "NO"
]

[kelvinharron]

@fortmarek @pepicrft, do you have a way to reproduce this error? I've made changes locally but want to prove it out. I think we had this one off a long time ago but our local macro + mockable has been trouble through

[pepicrft]

I can't remember the exact steps, but you can try to compile an app for a destination that requires signing, like a physical device. The build system might transitively try to sigh that artifact too.