Removing import functools from cp65001.py fixes test_startup_imports.

Victor proposed this PR: https://github.com/python/cpython/pull/13110
but new test_codecs fails because it's passing self on to the lambda I think.

I tried to build on Victor's change but there is still one test failure I haven't tracked down yet: https://github.com/python/cpython/pull/13211

FAIL: test_incremental_surrogatepass (test.test_codecs.CP65001Test)
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Traceback (most recent call last):
  File "C:\master\pythond\lib\test\test_codecs.py", line 436, in test_incremental_surrogatepass
    self.assertEqual(dec.decode(data[i:], True), '\uD901')
AssertionError: '' != '\ud901'
+ \ud901