kv: skip TestConstraintConformanceReportIntegration under deadlock

Fixes #108430.

This commit avoids flakiness in `TestConstraintConformanceReportIntegration`
by skipping the test under deadlock builds. It has been observed to run
slowly and flake under stress, and we see the same kinds of behavior under
deadlock builds.

Release notes: None

pkg/kv/kvserver/reports/reporter_test.go

@@ -47,6 +47,8 @@ func TestConstraintConformanceReportIntegration(t *testing.T) {
 	// don't make progress.
 	skip.UnderStressRace(t)
 	skip.UnderRace(t, "takes >1min under race")
+	// Similarly, skip the test under deadlock builds.
+	skip.UnderDeadlock(t, "takes >1min under deadlock")
 
 	ctx := context.Background()
 	tc := serverutils.StartNewTestCluster(t, 5, base.TestClusterArgs{