test_dis should test the dis module, not everything else

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2022-02-15.14:17:08.858>
labels = ['type-feature', 'tests']
title = 'test_dis should test the dis module, not everything else'
updated_at = <Date 2022-02-18.21:38:39.147>
user = 'https://github.com/markshannon'

bugs.python.org fields:

activity = <Date 2022-02-18.21:38:39.147>
actor = 'terry.reedy'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Tests']
creation = <Date 2022-02-15.14:17:08.858>
creator = 'Mark.Shannon'
dependencies = []
files = []
hgrepos = []
issue_num = 46760
keywords = ['patch']
message_count = 2.0
messages = ['413291', '413514']
nosy_count = 5.0
nosy_names = ['terry.reedy', 'Mark.Shannon', 'JelleZijlstra', 'brandtbucher', 'iritkatriel']
pr_nums = ['31369']
priority = 'normal'
resolution = None
stage = 'patch review'
status = 'open'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue46760'
versions = []