tempfile mkstemp() leaks file descriptors if os.close() is not called

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2021-01-05.11:28:47.432>
labels = ['3.8', 'library', 'performance']
title = 'tempfile mkstemp() leaks file descriptors if os.close() is not called'
updated_at = <Date 2021-07-09.20:49:19.364>
user = 'https://bugs.python.org/mieczyslawtorchala'

bugs.python.org fields:

activity = <Date 2021-07-09.20:49:19.364>
actor = 'andrei.avk'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2021-01-05.11:28:47.432>
creator = 'mieczyslaw.torchala'
dependencies = []
files = []
hgrepos = []
issue_num = 42830
keywords = ['patch']
message_count = 8.0
messages = ['384384', '385850', '385898', '397180', '397185', '397209', '397218', '397221']
nosy_count = 4.0
nosy_names = ['thatiparthy', 'andrei.avk', 'mieczyslaw.torchala', 'StillSubjectToChange']
pr_nums = ['27075']
priority = 'normal'
resolution = None
stage = 'patch review'
status = 'open'
superseder = None
type = 'resource usage'
url = 'https://bugs.python.org/issue42830'
versions = ['Python 3.8']