Exception from `importlib` when `eval`ing hy code that uses `require`

Cloneable reproducer: https://gist.github.com/KevinMGranger/78544bd6cccfde2c9b60baf3424ea87c

## Partial Cause

The same-module require check in `hy.macros.require` winds up with `target_module` (coming from `derive_target_module`) set to `None`