`fatxpool`: use tracing for logging #11759

Job	Run time
preflight / preflight	44s
preflight / ci-versions	1m 1s
check-revive-stable-uapi-polkavm	2m 10s
build-runtimes-polkavm	7m 42s
build-subkey	3m 53s
All build misc jobs passed	1s
	15m 31s

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