Fix some friend access violations by allowing others access. (#8594)

Rename Friend attribute to Access attribute.
Updates submodule to v0.21.0.0 as well.

Content.Server/Botany/Components/ProduceComponent.cs

@@ -4,7 +4,7 @@ using Robust.Shared.Serialization.TypeSerializers.Implementations.Custom.Prototy
 namespace Content.Server.Botany.Components;
 
 [RegisterComponent]
-[Friend(typeof(BotanySystem))]
+[Access(typeof(BotanySystem))]
 public sealed class ProduceComponent : Component
 {
     [DataField("targetSolution")] public string SolutionName { get; set; } = "food";