Replace codecs.open by open

The reason is a deprecation warning introduced with Python 3.14:

```
/opt/hostedtoolcache/Python/3.14.0-rc.2/x64/lib/python3.14/site-packages/publicsuffix2/__init__.py:86: DeprecationWarning: codecs.open() is deprecated. Use open() instead.
  with codecs.open(psl_file or PSL_FILE, 'r', encoding='utf8') as psl:
```

---

Signed-off-by: stefan6419846 <[email protected]>

Author: stefan6419846

src/publicsuffix2/__init__.py

@@ -83,7 +83,7 @@ def __init__(self, psl_file=None, idna=True):
         """
         # Note: we test for None as we accept empty lists as inputs
         if psl_file is None or isinstance(psl_file, str):
-            with codecs.open(psl_file or PSL_FILE, 'r', encoding='utf8') as psl:
+            with open(psl_file or PSL_FILE, 'r', encoding='utf8') as psl:
                 psl = psl.readlines()
         else:
             # assume file-like