Fix whl_library file path inference

Author: gholms

CHANGELOG.md

@@ -90,6 +90,7 @@ END_UNRELEASED_TEMPLATE
   various URL formats - URL encoded version strings get correctly resolved, sha256 value can be
   also retrieved from the URL as opposed to only the `--hash` parameter. Fixes
   [#2363](https://github.com/bazel-contrib/rules_python/issues/2363).
+* (pypi) `whl_library` now infers file names from its `urls` attribute correctly.
 
 {#v0-0-0-added}
 ### Added

python/private/pypi/whl_library.bzl

@@ -277,7 +277,7 @@ def _whl_library_impl(rctx):
             fail("could not download the '{}' from {}:\n{}".format(filename, urls, result))
 
         if filename.endswith(".whl"):
-            whl_path = rctx.path(rctx.attr.filename)
+            whl_path = rctx.path(filename)
         else:
             # It is an sdist and we need to tell PyPI to use a file in this directory
             # and, allow getting build dependencies from PYTHONPATH, which we