extensions: address ast deprecations introduced in Python 3.12 Tests would fail with: .../mercurial/extensions.py:910: DeprecationWarning: ast.Str is deprecated and will be removed in Python 3.14; use ast.Constant instead if isinstance(a, ast.Str): .../mercurial/extensions.py:912: DeprecationWarning: ast.Bytes is deprecated and will be removed in Python 3.14; use ast.Constant instead elif isinstance(a, ast.Bytes): .../mercurial/extensions.py:913: DeprecationWarning: Attribute s is deprecated and will be removed in Python 3.14; use value instead name = a.s