fix: flaky Test_RegistrySynchronizer1_3_UpkeepCheckDataUpdatedLog

Add initial check data verification before proceeding to the log
handling phase, matching the pattern used in the stable
UpkeepGasLimitSetLog test. This ensures fullSync has fully completed
and the run loop is in the select statement before the test sets up
new mocks and calls HandleLog. Also remove unused broadcast mock.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: aareet

core/services/keeper/registry1_3_synchronizer_test.go

@@ -707,9 +707,16 @@ func Test_RegistrySynchronizer1_3_UpkeepCheckDataUpdatedLog(t *testing.T) {
 	cltest.WaitForCount(t, db, "keeper_registries", 1)
 	cltest.WaitForCount(t, db, "upkeep_registrations", 1)
 
+	// Verify initial check data before proceeding to ensure fullSync is complete
+	g.Eventually(func() []byte {
+		var upkeep keeper.UpkeepRegistration
+		err := db.Get(&upkeep, `SELECT * FROM upkeep_registrations WHERE upkeep_id = $1`, sqlutil.New(upkeepId))
+		require.NoError(t, err)
+		return upkeep.CheckData
+	}, testutils.WaitTimeout(t), cltest.DBPollingInterval).Should(gomega.Equal(upkeepConfig1_3.CheckData))
+
 	head := cltest.MustInsertHead(t, db, 1)
 	rawLog := types.Log{BlockHash: head.Hash}
-	_ = logmocks.NewBroadcast(t)
 	newCheckData := []byte("Chainlink")
 	registryMock := cltest.NewContractMockReceiver(t, ethMock, keeper.Registry1_3ABI, contractAddress)
 	newConfig := upkeepConfig1_3