require at least python 3.10 and remove old runtime patch

pyquarantine/_runtime_patches.py

@@ -166,66 +166,3 @@ for alias in ["windows-874", "windows_874"]:
         aliases[alias] = "cp874"
 
 setattr(encodings.aliases, "aliases", aliases)
-
-
-if version_info.major == 3 and version_info.minor < 10:
-    # https://bugs.python.org/issue30681
-    #
-    # fix: https://github.com/python/cpython/pull/22090
-
-    import email.errors
-    from email.errors import HeaderDefect
-
-
-    class InvalidDateDefect(HeaderDefect):
-        """Header has unparseable or invalid date"""
-
-
-    setattr(email.errors, "InvalidDateDefect", InvalidDateDefect)
-
-
-    import email.utils
-    from email.utils import _parsedate_tz
-    import datetime
-
-
-    def parsedate_to_datetime(data):
-        parsed_date_tz = _parsedate_tz(data)
-        if parsed_date_tz is None:
-            raise ValueError('Invalid date value or format "%s"' % str(data))
-        *dtuple, tz = parsed_date_tz
-        if tz is None:
-            return datetime.datetime(*dtuple[:6])
-        return datetime.datetime(*dtuple[:6],
-                tzinfo=datetime.timezone(datetime.timedelta(seconds=tz)))
-
-
-    setattr(email.utils, "parsedate_to_datetime", parsedate_to_datetime)
-
-
-    import email.headerregistry
-    from email import utils, _header_value_parser as parser
-
-    @classmethod
-    def parse(cls, value, kwds):
-        if not value:
-            kwds['defects'].append(errors.HeaderMissingRequiredValue())
-            kwds['datetime'] = None
-            kwds['decoded'] = ''
-            kwds['parse_tree'] = parser.TokenList()
-            return
-        if isinstance(value, str):
-            kwds['decoded'] = value
-            try:
-                value = utils.parsedate_to_datetime(value)
-            except ValueError:
-                kwds['defects'].append(errors.InvalidDateDefect('Invalid date value or format'))
-                kwds['datetime'] = None
-                kwds['parse_tree'] = parser.TokenList()
-                return
-        kwds['datetime'] = value
-        kwds['decoded'] = utils.format_datetime(kwds['datetime'])
-        kwds['parse_tree'] = cls.value_parser(kwds['decoded'])
-
-
-    setattr(email.headerregistry.DateHeader, "parse", parse)

setup.py

@@ -49,5 +49,5 @@ setup(name = "pyquarantine",
         )
     ],
     install_requires = ["pymilter >= 1.5", "jsonschema", "netaddr", "beautifulsoup4[lxml]", "peewee"],
-    python_requires = ">=3.9"
+    python_requires = ">=3.10"
 )