Fix a flaky zombienet test - 0004-coretime-smoke-test #11981

Job	Run time
check-dependency-rules	11s
check-fail-ci	12s
check-markdown	15s
check-workspace	20s
preflight / preflight	41s
preflight / ci-versions	1m 28s
check-rust-feature-propagation	2m 11s
check-toml-format	1m 13s
check-umbrella	2m 30s
fmt	1m 11s
test-rust-features	2m 14s
All quick checks passed	1s
	12m 27s

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