gh-93121: change _sample_headers from a map to list + tuples to allow duplicates

[AGZain]

#93121

Before:

cpython/Lib/test/test_mailbox.py

Lines 34 to 35 in b2694ab

	for key, value in _sample_headers.items():
	self.assertIn(value, msg.get_all(key))

cpython/Lib/test/test_mailbox.py

Lines 2267 to 2290 in b2694ab

	_sample_headers = {
	"Return-Path":"<[email protected]>",
	"X-Original-To":"gkj+person@localhost",
	"Delivered-To":"gkj+person@localhost",
	"Received":"""from localhost (localhost [127.0.0.1])
	by andy.gregorykjohnson.com (Postfix) with ESMTP id 356ED9DD17
	for <gkj+person@localhost>; Wed, 13 Jul 2005 17:23:16 -0400 (EDT)""",
	"Delivered-To":"[email protected]",
	"Received":"""from localhost [127.0.0.1]
	by localhost with POP3 (fetchmail-6.2.5)
	for gkj+person@localhost (single-drop); Wed, 13 Jul 2005 17:23:16 -0400 (EDT)""",
	"Received":"""from andy.gregorykjohnson.com (andy.gregorykjohnson.com [64.32.235.228])
	by sundance.gregorykjohnson.com (Postfix) with ESMTP id 5B056316746
	for <[email protected]>; Wed, 13 Jul 2005 17:23:11 -0400 (EDT)""",
	"Received":"""by andy.gregorykjohnson.com (Postfix, from userid 1000)
	id 490CD9DD17; Wed, 13 Jul 2005 17:23:11 -0400 (EDT)""",
	"Date":"Wed, 13 Jul 2005 17:23:11 -0400",
	"From":""""Gregory K. Johnson" <[email protected]>""",
	"To":"[email protected]",
	"Subject":"Sample message",
	"Mime-Version":"1.0",
	"Content-Type":"""multipart/mixed; boundary="NMuMz9nt05w80d4+\"""",
	"Content-Disposition":"inline",
	"User-Agent": "Mutt/1.5.9i" }

Since _sample_headers is a map with duplicate keys (ex: Received), not all keys are tested.

After:

Changed _sample_headers to a list of tuples so all keys are tested

[ghost]

The following commit authors need to sign the Contributor License Agreement:

• [email protected]

Click the button to sign:

[bedevere-bot]

Most changes to Python require a NEWS entry.

Please add it using the blurb_it web app or the blurb command-line tool.