(joe) update news, turn finder into a public attribute of resolver cl…

…ass, test lack_sem_open false directly

news/10480.feature.rst

@@ -1 +1 @@
-Prepopulate find_all_candidates cache in parallel to reduce overhead when collecting packages to install.
+Parallelize network requests when finding package candidates for installation.

src/pip/_internal/resolution/resolvelib/resolver.py

@@ -54,7 +54,7 @@ def __init__(
     ):
         super().__init__()
         assert upgrade_strategy in self._allowed_strategies
-
+        self.finder = finder
         self.factory = Factory(
             finder=finder,
             preparer=preparer,
@@ -90,13 +90,8 @@ def resolve(
             reporter,
         )
 
-        if LACK_SEM_OPEN:
-            # if a working threading implementation unavailable do nothing
-            pass
-        else:
-            # otherwise greedily call/consume _finder.find_all_candidates in parallel
-            # in order to populate the lru cache such that future calls don't block on
-            # networking
+        if LACK_SEM_OPEN is False:
+
             def _maybe_find_candidates(req: Requirement) -> None:
                 ident = provider.identify(req)
                 try: