Tiny mobs can no longer pass on the zombie disease (#21676)

This reverts f391ff28 and implements an alternate messure where mice and other small animals can no longer infect people as zombies.

This is done through a component which if present cancels the check that would cause zombie components to be added on people that get infected due to a bite.

This still allows other special stuff that happens in that function that may affect already infected individuals.
This is a compromise between what's discussed in discord which would much rather see mice and other animals just die from the infection and people on github which would see no change happen.

Since bats can't go under doors it may not be necessary to make them non spreaders.
If someone disagrees please tell me to just add it back.

Content.Server/Zombies/NonSpreaderZombieComponent.cs

@@ -0,0 +1,10 @@
+namespace Content.Server.Zombies;
+
+/// <summary>
+/// Zombified entities with this component cannot infect other entities by attacking.
+/// </summary>
+[RegisterComponent]
+public sealed partial class NonSpreaderZombieComponent: Component
+{
+
+}

Content.Server/Zombies/ZombieImmuneComponent.cs

@@ -1,5 +1,8 @@
 namespace Content.Server.Zombies;
 
+/// <summary>
+/// Entities with this component cannot be zombified.
+/// </summary>
 [RegisterComponent]
 public sealed partial class ZombieImmuneComponent : Component
 {

Content.Server/Zombies/ZombieSystem.cs

@@ -219,7 +219,7 @@ namespace Content.Server.Zombies
                 }
                 else
                 {
-                    if (!HasComp<ZombieImmuneComponent>(entity) && _random.Prob(GetZombieInfectionChance(entity, component)))
+                    if (!HasComp<ZombieImmuneComponent>(entity) && !HasComp<NonSpreaderZombieComponent>(args.User) && _random.Prob(GetZombieInfectionChance(entity, component)))
                     {
                         EnsureComp<PendingZombieComponent>(entity);
                         EnsureComp<ZombifyOnDeathComponent>(entity);

Resources/Prototypes/Entities/Mobs/NPCs/animals.yml

@@ -313,6 +313,7 @@
         damage: 10
       behaviors:
       - !type:GibBehavior { }
+  - type: NonSpreaderZombie
 
 - type: entity
   name: glockroach
@@ -1272,6 +1273,7 @@
   - type: Puller
     needsHands: true
   - type: BadFood
+  - type: NonSpreaderZombie
 
 - type: entity
   parent: MobMouse
@@ -2690,6 +2692,7 @@
     BaseResistTime: 3
   - type: MobPrice
     price: 60
+  - type: NonSpreaderZombie
 
 - type: entity
   name: pig

Resources/Prototypes/Entities/Mobs/NPCs/spacetick.yml

@@ -84,6 +84,7 @@
     accent: genericAggressive
   - type: Speech
     speechVerb: SmallMob
+  - type: NonSpreaderZombie
 
 - type: entity
   id: MobTickSalvage