doc: correct traceQL metrics documentation #9442

Job	Run time
Lint	3m 34s
Build	1m 51s
Run integration tests (test-e2e)	20m 29s
Run integration tests (test-integration-poller)	14m 54s
Run integration tests (test-e2e-deployments)	13m 23s
Run Unit Tests (test-with-cover-pkg)	3m 13s
Run integration tests (test-e2e-serverless)	7m 8s
Benchmark	9m 31s
Run Unit Tests (test-with-cover-tempodb)	15m 39s
Build technical documentation	19s
Check jsonnet & tempo-mixin	49s
Run Unit Tests (test-with-cover-tempodb-wal)	11m 28s
Vendor check	1m 27s
Run Unit Tests (test-with-cover-others)	12m 15s
	1h 56m 0s

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