Fix memory leak in quic_trace.c #389

Job	Run time
address_ub_sanitizer	10m 7s
basic_clang	4m 52s
basic_gcc	4m 57s
check_docs	56s
check_update	1m 14s
check-ansi	2m 31s
enable_non-default_options	4m 6s
external-test-cf-quiche	3m 32s
external-test-pyca (1.51.0, 3.9)	6m 22s
external-tests	11m 4s
fips_and_ktls	4m 47s
fuzz_tests	2m 52s
legacy	3m 44s
memory_sanitizer	20m 37s
minimal	2m 25s
no-deprecated	4m 24s
no-legacy	4m 54s
no-shared-macos (macos-13)	6m 21s
non-caching	13m 10s
no-shared-ubuntu	3m 38s
no-shared-macos (macos-14)	3m 30s
out-of-readonly-source-and-install-macos (macos-13)	10m 16s
out-of-readonly-source-and-install-macos (macos-14)	5m 15s
out-of-readonly-source-and-install-ubuntu	6m 31s
self-hosted	0s
threads_sanitizer	4m 50s
	2h 26m 55s

Provide feedback