Fix running Tuist.graph() in a Tuist task

[fortmarek]

Short description 📝

This PR should fix the current tasks that could not find the tuist executable. The primary issue was that we were not passing the tuist executable properly. We want to move away from the model where tuist triggers the tuist task which triggers tuist again. Instead, we want the tuist task to be a regular Swift CLI that just uses the ProjectAutomation framework to be able to easily decode the graph to a Swift model from the tuist graph --format json invocation.

I hope to prepare a long-term proposal for tuist tasks future soon as the current setup has a lot of indirection and unnecessary maintenance costs for us.

How to test the changes locally 🧐

You can test the functionality by running swift run --package-path InspectGraph inspect-graph inside the app_with_plugins fixture.

Contributor checklist ✅

• The code has been linted using run mise run lint:fix
• The change is tested via unit testing or acceptance testing, or both
• The title of the PR is formulated in a way that is usable as a changelog entry
• In case the PR introduces changes that affect users, the documentation has been updated

Reviewer checklist ✅

• The code architecture and patterns are consistent with the rest of the codebase
• Reviewer has checked that, if needed, the PR includes the label changelog:added, changelog:fixed, or changelog:changed, and the title is usable as a changelog entry