fix(registry-auth): scoped the legacy token in the npmrc to the registry

[travi]

fixes #530

[travi]

it looks like this only became scope-able to a registry in npm v8, so this would not be a backward compatible change for all of the node versions currently supported by this plugin.

since the official registry has not supported this legacy approach to auth for some time and registries other than the official registry require legacy auth to be scoped to a registry, this would only impact use with projects targeting alternative registries that are not yet using npm v8.

quite honestly, since artifactory was the primary reason that legacy auth support was added to semantic-release in the first place, and artifactory does now support token auth, i lean toward removing legacy auth support altogether rather than fixing it for npm v9.

[gr2m]

since artifactory was the primary reason that legacy auth support was added to semantic-release in the first place, and artifactory does now support token auth, i lean toward removing legacy auth support altogether rather than fixing it for npm v9.

Agree 💯