Respect `pyproject.toml` credentials from user-provided requirements (#7474)
## Summary
When syncing a lockfile, we need to respect credentials defined in the
`pyproject.toml`, even if they won't be used for resolution.
Unfortunately, this includes credentials in `tool.uv.sources`,
`tool.uv.dev-dependencies`, `project.dependencies`, and
`project.optional-dependencies`.
Closes https://github.com/astral-sh/uv/issues/7453.