Hadrian does not respect the bootstrap GHC

Summary

Hadrian picks whatever ghc is in PATH and ignores the bootstrap GHC that was passed to ./configure GHC=/some/path/to/ghc of the GHC sources.

Logs: https://gitlab.haskell.org/-/snippets/5748

Steps to reproduce

ghcup -v compile ghc --version 9.10.0.20240413 -b /root/.ghcup/bin/ghc-9.8.2 --hadrian --flavour=default+native_bignum

Expected behavior

Hadrian respects the bootstrap GHC (why would it not?).

Environment

• GHC version used: 9.10.0.20240413
• bootstrap version: 9.8.2

Optional:

• Operating System: Rocky Linux 8
• System Architecture: x86_64