Rename SingleModuleReference::asset to SingleModuleReference::module (#92028)
The field holds a Module, not a generic asset. This aligns the naming
with the type it actually stores.
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Co-authored-by: Tobias Koppers <sokra@users.noreply.github.com>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Benjamin Woodruff <bgw@users.noreply.github.com>