[3.14] gh-140141: Properly break exception chain in importlib.metadata.Distribution.from_name (GH-140142)

(cherry picked from commit bcced02)

Co-authored-by: Bartosz Sławecki <[email protected]>

Author: bswck

Lib/importlib/metadata/__init__.py

@@ -406,7 +406,7 @@ def from_name(cls, name: str) -> Distribution:
         try:
             return next(iter(cls.discover(name=name)))
         except StopIteration:
-            raise PackageNotFoundError(name)
+            raise PackageNotFoundError(name) from None
 
     @classmethod
     def discover(

Misc/NEWS.d/next/Library/2025-10-15-17-23-51.gh-issue-140141.j2mUDB.rst

@@ -0,0 +1,5 @@
+The :py:class:`importlib.metadata.PackageNotFoundError` traceback raised when
+``importlib.metadata.Distribution.from_name`` cannot discover a
+distribution no longer includes a transient :exc:`StopIteration` exception trace.
+
+Contributed by Bartosz Sławecki in :gh:`140142`.