next.js

f6663b75 - Turbopack: Dedupe our two filesystempath extension/extension_ref functions (#92048)

Turbopack: Dedupe our two filesystempath extension/extension_ref functions (#92048) PR is AI-generated - `extension` and `extension_ref` do the same thing. - `extension_ref`'s API that returns an `Option` was better than `extension`'s API that returns a potentially-empty string. - In some places we were splitting into a stem and extension, and joining them back to a filename, but those places could just get the original path's filename. --------- 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>