chore: update iterations to protect against race (anchore#1927)

* chore: update iterations to protect against race
---------

Signed-off-by: Christopher Phillips <christopher.phillips@anchore.com>

cmd/syft/cli/ui/handle_attestation_test.go

@@ -28,7 +28,7 @@ func TestHandler_handleAttestationStarted(t *testing.T) {
 			// note: this model depends on a background reader. Multiple iterations ensures that the
 			// reader has time to at least start and process the test fixture before the runModel
 			// test harness completes (which is a fake event loop anyway).
-			iterations: 2,
+			iterations: 100,
 			eventFn: func(t *testing.T) partybus.Event {
 				reader := strings.NewReader("contents\nof\nstuff!")
 
@@ -61,7 +61,7 @@ func TestHandler_handleAttestationStarted(t *testing.T) {
 			// note: this model depends on a background reader. Multiple iterations ensures that the
 			// reader has time to at least start and process the test fixture before the runModel
 			// test harness completes (which is a fake event loop anyway).
-			iterations: 2,
+			iterations: 100,
 			eventFn: func(t *testing.T) partybus.Event {
 				reader := strings.NewReader("contents\nof\nstuff!")