Drop use_user_site argument from prepare_editable_requirement

Author: pradyunsg

src/pip/_internal/legacy_resolve.py

@@ -269,9 +269,7 @@ def _get_abstract_dist_for(self, req):
         representing a prepared variant of the same.
         """
         if req.editable:
-            return self.preparer.prepare_editable_requirement(
-                req, self.use_user_site
-            )
+            return self.preparer.prepare_editable_requirement(req)
 
         # satisfied_by is only evaluated by calling _check_skip_installed,
         # so it must be None here.

src/pip/_internal/operations/prepare.py

@@ -686,7 +686,6 @@ def prepare_linked_requirement(
     def prepare_editable_requirement(
         self,
         req,  # type: InstallRequirement
-        use_user_site,  # type: bool
     ):
         # type: (...) -> AbstractDistribution
         """Prepare an editable requirement
@@ -711,7 +710,7 @@ def prepare_editable_requirement(
 
             if self._download_should_save:
                 req.archive(self.download_dir)
-            req.check_if_exists(use_user_site)
+            req.check_if_exists(self.use_user_site)
 
         return abstract_dist