gh-139308: Skip test_special_chars_csh on NetBSD due to csh variable expansion issue (GH-139341)

Skip test_special_chars_csh on NetBSD due to csh variable expansion issue
(cherry picked from commit ae6e7f5)

Co-authored-by: Furkan Onder <furkanonder@protonmail.com>
Co-authored-by: Filipe Laíns 🇵🇸 <lains@riseup.net>

Author: 2 people

Lib/test/test_venv.py

@@ -522,6 +522,8 @@ def test_special_chars_bash(self):
 
     # gh-124651: test quoted strings
     @unittest.skipIf(os.name == 'nt', 'contains invalid characters on Windows')
+    @unittest.skipIf(sys.platform.startswith('netbsd'),
+                     "NetBSD csh fails with quoted special chars; see gh-139308")
     def test_special_chars_csh(self):
         """
         Test that the template strings are quoted properly (csh)