Firefly particles continue to animate after the game has been paused.

The Firefly particles produced by the Firefly bush continue to be active for some time even after the game has been paused.

Steps to reproduce:

1. Launch Minecraft Preview (1.21.70.20)
2. Create a new world in creative mode
3. Place down a few Firefly Bushes
4. Set the time to night (You can use this command: /time set night)
5. Pause the game

Expected Result:

The Firefly particles freeze in place, and to not disappear.

Observed result:

The Firefly particles continue to animate for some time and then eventually disappear.

Notes: 

This is related to the issue mentioned at MCPE-188461.