fix: give better errors on broken pyproject.toml

[ruben-arts]

You'll now get:

$ pixi install
  × failed to parse project manifest
    ╭─[pyproject.toml:18:12]
 17 │ 
 18 │ [tool.pixi.pypi-depenencies]
    ·            ────────┬───────
    ·                    ╰── unknown field `pypi-depenencies`, expected one of `project`, `system-requirements`, `target`, `dependencies`, `host-dependencies`, `build-dependencies`, `pypi-dependencies`, `activation`, `tasks`, `feature`, `environments`, `pypi-options`, `tool`, `$schema`
 19 │ test_init = { path = ".", editable = true }
    ╰────

instead of:

❯ ~/.pixi/bin/pixi i
  × could not find pixi.toml or pyproject.toml which is configured to use pixi

[baszalmstra]

The reason we did it this way is to be able to have a nested subdirectory that contains a non-pixi pyproject and a top level pixi project.

With this PR this will fail if the current directory is the nested subdirectory.

Instead, I think we should try to loosely parse the toml file and see if it contains a tool.pixi section.

[baszalmstra]

This will change the current directory for all tests. Please modify the code so that it can recieve the current directory instead of reading it from the environment.

[ruben-arts]

Lol, that was a bit extreme. Improved the find function!

[ruben-arts]

@baszalmstra I re-enabled the pyproject validation code but only or the [tool.pixi search not the full parse.

[baszalmstra]

nice!