In reply to @xtrayambak "as laylie said, those": do they? i feel like it's
pretty common for package managers to read a single project definition file. in
js land, npm, pnpm, yarn, bun all read `package.json`. like aethrvmn said,
`pyproject.toml` is read by poetry, uv, hatch, pip, etc. ruby has gemfiles.
python has build-tool specific metadata in `pyproject.toml` where applicable but
there usually isn't a lot of that because the project definition specification
is useful enough to not need any build-tool specific configuration