Revert "Solution Entities" (#23160)

Revert "Solution Entities (#21916)"

This reverts commit d75e743dd7.

Content.Server/Botany/Components/PlantHolderComponent.cs

@@ -1,4 +1,3 @@
-using Content.Shared.Chemistry.Components;
 using Robust.Shared.Serialization.TypeSerializers.Implementations.Custom;
 
 namespace Content.Server.Botany.Components;
@@ -91,7 +90,4 @@ public sealed partial class PlantHolderComponent : Component
 
     [ViewVariables(VVAccess.ReadWrite), DataField("solution")]
     public string SoilSolutionName = "soil";
-
-    [DataField]
-    public Entity<SolutionComponent>? SoilSolution = null;
 }