Turtle eggs are not in the "Spawn Eggs" tab in the Creative inventory

Relates to MC-278783.

The bug

minecraft:turtle_egg is not present in the Spawn Eggs tab in the Creative inventory. This is despite the fact that they are an item that can be used to spawn mobs. Other non-spawn egg items that spawn mobs are also in this tab (i.e. spawners, trial spawners, creaking hearts), so the exclusion of eggs seems unexpected.

How to fix

Add minecraft:turtle_egg to the Spawn Eggs tab.