nightly

Auto merge of #12044 - tedinski:fix_rustc_workspace, r=jonas-schievink

fix: index the correct CargoWorkspace with rustc_private

I believe this fixes #12043, but I'm not sufficiently setup/familiar with working on rust-analyzer to test it locally. :/

This section of code is iterating on `rustc_workspace.packages()` but then indexes `cargo[pkg]`, which is likely the source of the bug.