Fix show() on non-UTC Kerberos #6405

Job	Run time
Type hints check	27s
ubuntu-latest 3.7 non_root -K scanner	3m 25s
CodeQL analysis	3m 5s
ubuntu-latest 3.8 non_root -K scanner	4m 18s
Build doc	5m 59s
Code health check	1m 17s
ubuntu-latest 3.9 non_root -K scanner	3m 40s
ubuntu-latest 3.10 non_root -K scanner	3m 34s
pyca/cryptography test	22s
ubuntu-latest 3.11 non_root -K scanner	3m 28s
ubuntu-latest 3.12 non_root -K scanner	4m 7s
ubuntu-latest 3.12 root -K scanner	5m 7s
ubuntu-latest pypy3.9 root -K scanner	4m 29s
ubuntu-latest libpcap 3.12 root -K scanner	6m 7s
macos-12 3.12 both -K scanner	7m 15s
ubuntu-latest 3.12 root -k scanner	4m 27s
ubuntu-latest pypy3.9 root -k scanner	3m 39s
macos-12 3.12 both -k scanner	2m 51s
	1h 7m 37s

Provide feedback