Remove special treatment of eiger in waiting for connection

[DominicOram]

Following DiamondLightSource/dodal@61dc775 all PVs in the Eiger should now be able to connect to the device. Previously, because this wasn't the case we were not waiting for the Eiger to connect unlike other devices. We should make it wait to match other Devices.

Acceptance Criteria

• Confirm the Eiger now connects happily
• Remove any mention in the codebase of not waiting for the Eiger

[DominicOram]

Tested that test_i03_system.py in dodal still works and eiger is being connected to as other devices