cgi module removal

[decaz]

DeprecationWarning: 'cgi' is deprecated and slated for removal in Python 3.13

cgi is used here:

python-zeep/src/zeep/utils.py

Lines 91 to 94 in 4e5ebad

	def get_media_type(value):
	"""Parse a HTTP content-type header and return the media-type"""
	main_value, parameters = cgi.parse_header(value)
	return main_value.lower()

As a replacement of parse_header function PEP 594 suggests to use email.message.Message.

[arveitch]

Could I request a release please as Python 3.13 is getting quite close. Thanks so much for an excellent product!