Backport fix staking benchmark (#6463) to stable 2412 and disable flaky tests #15185

Job	Run time
check-dependency-rules	6s
check-markdown	13s
check-fail-ci	9s
check-workspace	15s
preflight / preflight	41s
preflight / ci-versions	1m 6s
fmt	1m 15s
check-rust-feature-propagation	2m 9s
check-toml-format	1m 1s
check-umbrella	2m 24s
test-rust-features	2m 8s
All quick checks passed	1s
	11m 28s

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