10503: Only include targets of packages that are workspace members r=Veykril a=bcully
CargoWorkspace's package list includes packages that are path
dependencies, even if those packages aren't actually members of the
cargo workspace. As a result, rust-analyzer's runnable finder, which
returns the target from the first workspace that has a matching package,
may select the wrong working directory, causing runnables to fail, e.g.,
```
error: package `root` cannot be tested because it requires dev-dependencies and is not a member of the workspace
```
To fix this, we filter out packages that aren't members of the workspace
when searching for targets.
Fixes#7764
Co-authored-by: Brendan Cully <brendan@cully.org>
c5354877c9