test_seek_end and test_seek_current fails due to regression in Python 3.12.0a1+.

[hrnciar]

While building pyfilesystem2 with development versions of Python 3.12 I discovered a regression in CPython. You can find details and reproducer here.

=================================== FAILURES ===================================
________________________ TestReadZipFSMem.test_seek_end ________________________

self = <tests.test_zipfs.TestReadZipFSMem testMethod=test_seek_end>

def test_seek_end(self):
    with self.fs.openbin("top.txt") as f:
        self.assertEqual(f.tell(), 0)
        self.assertEqual(f.seek(-12, Seek.end), 0)
        self.assertEqual(f.read1(5), b"Hello")
        self.assertEqual(f.seek(-7, Seek.end), 5)
        self.assertEqual(f.seek(-5, Seek.end), 7)

      self.assertEqual(f.read(), b"World")

E AssertionError: b'' != b'World'

tests/test_zipfs.py:170: AssertionError
______________________ TestReadZipFSMem.test_seek_current ______________________

self = <tests.test_zipfs.TestReadZipFSMem testMethod=test_seek_current>

def test_seek_current(self):
    with self.fs.openbin("top.txt") as f:
        self.assertEqual(f.tell(), 0)
        self.assertEqual(f.read(5), b"Hello")
        self.assertEqual(f.tell(), 5)
        self.assertEqual(f.seek(2, Seek.current), 7)

      self.assertEqual(f.read1(), b"World")

E AssertionError: b'' != b'World'

tests/test_zipfs.py:156: AssertionError

FAILED tests/test_zipfs.py::TestReadZipFSMem::test_seek_end - AssertionError:...
FAILED tests/test_zipfs.py::TestReadZipFSMem::test_seek_current - AssertionEr...