Cabal does not yet support only building bytecode objects/libraries

Cabal proposal: https://github.com/haskell/cabal-proposals/blob/master/proposals/bytecode-files.md
MR which implements bytecode library support in Cabal: https://github.com/haskell/cabal/pull/11386

At the moment the GHC ecosystem doesn't support building only bytecode objects/libraries. They have to be compiled along with static/dynamic objects. Therefore `cabal-install` does not support only building bytecode objects.

You can trigger this bug by running `cabal-install` with:

```
cabal build --disable-library-vanilla --disable-shared --enable-library-bytecode
```

If you have run into this issue, please leave a comment on this ticket so that the demand for this feature is visible.