pyproject.toml: update prehistoric build-system

I got struck by this problem:

   python-poetry/poetry#7583

While trying to install `gluetool-modules-internal` with path
dependency on `gluetool-modules-framework` with `develop = true`.

```
  • Installing gluetool-modules-framework (0.9.0 /var/home/mvadkert/git/gitlab.com/testing-farm/gluetool-modules): Failed

  ChefBuildError

  Backend operation failed: HookMissing('build_editable')
```

This resolves the problem.

Signed-off-by: Miroslav Vadkerti <[email protected]>

pyproject.toml

@@ -191,5 +191,5 @@ types-simplejson = "*"
 development = ["ipdb"]
 
 [build-system]
-requires = ["poetry>=0.12"]
-build-backend = "poetry.masonry.api"
+requires = ["poetry>=1.0.0"]
+build-backend = "poetry.core.masonry.api"