Fix S3 file URI unit tests for Python 3.14.
Avoid urllib.request.pathname2url() when constructing local file URIs
in tests. Its behavior on Python 3.14 introduces additional leading
slashes, causing URI path assertions to fail.
Use the original temporary directory path directly to match the
behavior of boto.storage_uri().
--- ../tests/unit/s3/test_uri.py	2026-10-18 01:29:06.156046943 +0300
+++ ../tests/unit/s3/test_uri.py	2026-10-18 01:29:31.851511688 +0300
@@ -184,7 +184,7 @@
 
     def test_explicit_file_uri(self):
         tmp_dir = tempfile.tempdir or ''
-        uri_str = 'file://%s' % urllib.request.pathname2url(tmp_dir)
+        uri_str = 'file://%s' % tmp_dir
         uri = boto.storage_uri(uri_str, validate=False,
             suppress_consec_slashes=False)
         self.assertEqual('file', uri.scheme)
@@ -205,7 +205,7 @@
 
     def test_implicit_file_uri(self):
         tmp_dir = tempfile.tempdir or ''
-        uri_str = '%s' % urllib.request.pathname2url(tmp_dir)
+        uri_str = tmp_dir
         uri = boto.storage_uri(uri_str, validate=False,
             suppress_consec_slashes=False)
         self.assertEqual('file', uri.scheme)