Handle empty path expansion

[QuantumEntangledAndy]

I was getting an issue on Linux specifically

  File "site-packages/browser_cookie3/__init__.py", line 144, in _expand_paths_impl
    for path in paths:
                ^^^^^
  File "<frozen posixpath>", line 232, in expanduser

Investigation showed that

browser_cookie3/browser_cookie3/__init__.py

Lines 469 to 474 in 0389579

	self.v11_empty_key = PBKDF2(
	b'', self.salt, self.length, iterations)
	cookie_file = self.cookie_file or _expand_paths(
	linux_cookies, 'linux')

has an empty path for linux_cookies for browsers such as Arc which is I believe correct since there is no linux path for this browser

The issue is that the current implementation tries all browsers and for any browser where the linuxpath is not set it would error for linux.

To fix this I altered _expand_path_impl to handle empty (i.e. None) as an empty list instead

browser_cookie3/browser_cookie3/__init__.py

Lines 130 to 133 in 0389579

	def _expand_paths_impl(paths: list, os_name: str):
	"""Expands user paths on Linux, OSX, and windows"""
	os_name = os_name.lower()

def _expand_paths_impl(paths: list | None, os_name: str):
    """Expands user paths on Linux, OSX, and windows"""
    if paths is None:
         paths = []
    os_name = os_name.lower()