mailbox, mimetypes, unittest, zipfile: stubtest fixes (#5239)

tests/stubtest_whitelists/py38.txt

@@ -95,7 +95,6 @@ typing.SupportsInt.__init__
 typing.SupportsRound.__init__
 typing._SpecialForm.__init__
 typing._SpecialForm.__new__
-unittest.doModuleCleanups
 uuid.getnode  # undocumented, unused parameter getters that was later removed
 weakref.WeakValueDictionary.update
 webbrowser.Opera.raise_opts
@@ -103,7 +102,6 @@ xml.etree.ElementTree.TreeBuilder.start  # Discrepancy between Python and C modu
 xml.etree.ElementTree.XMLParser.__init__  # Defined in C so has general signature
 xml.etree.cElementTree.TreeBuilder.start  # bpo-39495
 xml.etree.cElementTree.XMLParser.__init__  # Defined in C so has general signature
-zipfile.Path.open
 # These enums derive from (int, IntEnum) or (str, Enum). See comment in py3_common.txt
 enum.IntFlag.__new__
 pstats.SortKey.__new__

tests/stubtest_whitelists/py3_common.txt

@@ -168,15 +168,7 @@ lib2to3.pytree.BasePattern.__new__
 lib2to3.pytree.BasePattern.type
 lib2to3.pytree.NegatedPattern.match
 lib2to3.pytree.NegatedPattern.match_seq
-mailbox.Babyl.__init__
-mailbox.MH.__init__
-mailbox.MMDF.__init__
-mailbox._mboxMMDF.get_bytes
-mailbox._mboxMMDF.get_file
-mailbox._mboxMMDF.get_string
-mailbox.mbox.__init__
-mimetypes.read_mime_types
-mmap.mmap.__iter__
+mmap.mmap.__iter__  # has __getitem__ but mypy doesn't derive __iter__ from it: https://github.com/python/mypy/issues/2220
 multiprocessing.JoinableQueue
 multiprocessing.Queue
 multiprocessing.SimpleQueue