bug#50885: [PATCH] import: go: Recognize major version suffixes.

[Ludovic Courtès]

Sarah Morgensen <iskarian@mgsn.dev> skribis:

> Do not treat major version suffixes (such as "/v3") as repository
> subdirectories.  See <https://golang.org/ref/mod#major-version-suffixes>.
>
> * guix/import/go.scm (go-module->guix-package): When determining the
> unpack path, compare 'root-module-path' to 'module-path-sans-suffix'
> instead of 'module-path'.

Applied as well, but I feel that it may be useful to have tests for
these fine points that where regressions would otherwise be hard to
notice.

Thanks,
Ludo’.