[zombieli]

When prepare_metadata_for_build_editable returns an invalid value, BackendFailed.exc_msg currently names prepare_metadata_for_build_wheel. Report the hook that was actually called and correct the existing regression expectation.

Validation on Windows / Python 3.13.1:

• The corrected expectation fails on the upstream implementation, then passes with this fix.
• Four focused editable/wheel metadata tests pass.
• The full suite has 94 passes and 8 symlink-permission failures (WinError 1314); the unchanged upstream baseline has the same 8 failures.
• Ruff checks/formatting on the changed files and ty check on source/tests pass.

Prepared with OpenAI Codex assistance.