Fleeet adapter publshing open and close door requests almost simultaneously

[cwrx777]

Issue summary:
when robot is at waypoint before the door and then given a task that will use the door, fleet adapter will keep publishing open and close door request simultaneously.

rmf_ros2 ceab18b

Steps to replicate:

Modify office map:

1. name waypoints before and after coe_door: IN_COE, OUT_COE`
2. set spawn_robot_name and spawn_robot_type at IN_COE as shown
3. remove tinyRobot1 from tinyRobot1_charger

Fleet adapter config:

finishing_request: "nothing"
responsive_wait: False

Run task:

ros2 run rmf_demos_tasks dispatch_patrol -p OUT_COE -F TinyRobot -R tinyRobot1 --use_sim_time

Result: