When building a dependency, its (unusedd) internal libraries are also built

```
% time cabal build vector
Configuration is affected by the following files:
- cabal.project
- cabal.project.local
Build profile: -w ghc-9.12.1 -O1
In order, the following will be built (use -v for more details):
- vector-0.13.2.0 (lib) (requires build)
- vector-0.13.2.0 (lib:benchmarks-O2) (requires build)
```

The `lib:benchmarks-O2` is used only by benchmarks, but it's still built. The `vector:lib:vector` target is not recognised.