Yarn Berry: remove unused code

There's no need for Cachi2 to directly access the contents of the
"npmRegistryServer" yarn_rc variable, since Yarn itself will read it
when we execute "yarn install". The code refering to it is a leftover of
the development phase.

In a similar way, there's no use in setting "unsafeHttpWhitelist" as an
empty list by default, since Cachi2 will purposefully set it to an empty
list as a way to overwrite any unwanted user configuration.

Signed-off-by: Bruno Pimentel <[email protected]>

cachi2/core/package_managers/yarn/project.py

@@ -65,22 +65,9 @@ class YarnRc(ConfigurationFile):
     _defaults = {
         "cacheFolder": "./.yarn/cache",
         "lockfileFilename": "yarn.lock",
-        "unsafeHttpWhitelist": [],
         "plugins": [],
-        "npmRegistryServer": "https://registry.yarnpkg.com",
     }
 
-    def registry_server_for_scope(self, scope: str) -> str:
-        """Get the configured registry server for a scoped package.
-
-        Fallback to the global defined registry server if there's no configuration for this specific
-        scope.
-
-        See: https://v3.yarnpkg.com/configuration/yarnrc#npmScopes
-        """
-        registry = self.data.get("npmScopes", {}).get(scope, {}).get("npmRegistryServer")
-        return registry or self["npmRegistryServer"]
-
     def write(self) -> None:
         """Write the data to the yarnrc file."""
         with self._path.path.open("w") as f: