PEP 723: use a new `[run]` table instead of `[project]`?

I am in agreement if the initial version also defines support for requires-python.

I understand folks seem to be coalescing on a comment, however I feel the need to say I spoke to one of the people that I mentioned in the PEP over the weekend who is already using the variable approach and while their response in support of that is rather lengthy I can post an exerpt:

[…] My first serious iteration, then, was having the module docstring look like this:

"""pyproject.toml
[project]
...
"""

…which pleasantly looks like a code fence. And I thought, you could also allow it as a top-level string literal immediately following the module docstring. But in the end, even though I still think this variant looks nicest, I went with __pyproject__ because it seemed more explicit and unambiguous.

I actually really like that idea.