Why does "cabal info" require ghc?

My CI script uses `cabal info` command and it fails like this:

```
cutlass:/vol/hosts/cueball/workspace/packages/streamly  (ghcjs2)$ cabal info .
cabal: The program 'ghc' version >=7.0.1 is required but it could not be
found.
```

I am running the script for `ghcjs` build and I have ghcjs installed but I do not need `ghc` for the build. Why is `ghc` required for this command to work?

```
cutlass:/vol/hosts/cueball/workspace/packages/streamly  (ghcjs2)$ cabal --version
cabal-install version 2.4.0.0
compiled using version 2.4.0.1 of the Cabal library
```

Start by reproducing `cabal info .` with cabal-install 2.4.0.0 in an environment with ghcjs but no ghc. Trace the command's compiler check and determine whether requiring ghc is expected; done means the behavior is explained and any needed change is covered by an appropriate regression test.

Written by the indexing model from the issue text.