Very slow upload with http.client on Windows when setting timeout

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2018-06-11.17:49:58.180>
labels = ['3.9', 'expert-IO', 'performance', 'library', '3.10', 'OS-windows']
title = 'Very slow upload with http.client on Windows when setting timeout'
updated_at = <Date 2021-10-21.14:52:53.071>
user = 'https://github.com/ivknv'

bugs.python.org fields:

activity = <Date 2021-10-21.14:52:53.071>
actor = 'ivknv'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)', 'Windows', 'IO']
creation = <Date 2018-06-11.17:49:58.180>
creator = 'ivknv'
dependencies = []
files = []
hgrepos = []
issue_num = 33838
keywords = []
message_count = 1.0
messages = ['319323']
nosy_count = 5.0
nosy_names = ['paul.moore', 'tim.golden', 'zach.ware', 'steve.dower', 'ivknv']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'performance'
url = 'https://bugs.python.org/issue33838'
versions = ['Python 3.6', 'Python 3.9', 'Python 3.10']