Check for cabal-install >= 3.12 upfront

Ticket: #27317 (closed)

Starting with commit 8cb99552, Hadrian requires cabal-install >= 3.12 in order to use the 'cabal path' command that was introduced in version 3.12, as per the release notes.

This was not reflected in the Hadrian build script, causing a delayed build failure instead of enforcing the version requirement upfront. This MR fixes that.