Show a concise error message for missing version field (#9912)
## Summary
This now looks like:
```
error: Failed to parse: `pyproject.toml`
Caused by: TOML parse error at line 1, column 1
|
1 | [project]
| ^^^^^^^^^
`pyproject.toml` is using the `[project]` table, but the required `project.version` field is neither set nor present in the `project.dynamic` list
```
Closes https://github.com/astral-sh/uv/issues/9910.
