cli/demo: start job scheduler right away

Previously we started it quickly but only in the system tenant. Now we start it quickly in all.
Also run it more often.

Release note: none.
Epic: none.

Author: dt

pkg/cli/democluster/demo_cluster.go

@@ -535,6 +535,15 @@ func (c *transientCluster) startTenantService(
 						InjectedLatencyEnabled: c.latencyEnabled.Load,
 					},
 				},
+				JobsTestingKnobs: &jobs.TestingKnobs{
+					// Allow the scheduler daemon to start earlier in demo.
+					SchedulerDaemonInitialScanDelay: func() time.Duration {
+						return time.Second * 2
+					},
+					SchedulerDaemonScanDelay: func() time.Duration {
+						return time.Second * 5
+					},
+				},
 			},
 		}
 
@@ -563,6 +572,15 @@ func (c *transientCluster) startTenantService(
 							InjectedLatencyEnabled: c.latencyEnabled.Load,
 						},
 					},
+					JobsTestingKnobs: &jobs.TestingKnobs{
+						// Allow the scheduler daemon to start earlier in demo.
+						SchedulerDaemonInitialScanDelay: func() time.Duration {
+							return time.Second * 2
+						},
+						SchedulerDaemonScanDelay: func() time.Duration {
+							return time.Second * 5
+						},
+					},
 				},
 			})
 		if err != nil {
@@ -924,7 +942,10 @@ func (demoCtx *Context) testServerArgsForTransientCluster(
 			JobsTestingKnobs: &jobs.TestingKnobs{
 				// Allow the scheduler daemon to start earlier in demo.
 				SchedulerDaemonInitialScanDelay: func() time.Duration {
-					return time.Second * 15
+					return time.Second * 2
+				},
+				SchedulerDaemonScanDelay: func() time.Duration {
+					return time.Second * 5
 				},
 			},
 		},