Flaky test: TestPrometheusCompatibilityQueryFuzz

[dsabsay]

See on #6650

    query_fuzz_test.go:1649: 
        	Error Trace:	/home/runner/work/cortex/cortex/integration/query_fuzz_test.go:1649
        	            				/home/runner/work/cortex/cortex/integration/query_fuzz_test.go:1534
        	Error:      	finished query fuzzing tests
        	Test:       	TestPrometheusCompatibilityQueryFuzz
        	Messages:   	1 test cases failed