Add Commands::insert_resource_if_neq (#24082)

# Objective

- Fixes #24041

## Testing

-
[`insert_resource_if_not_equal`](https://github.com/micttyoid/bevy/blob/command-insert-resource-if-neq/crates/bevy_ecs/src/system/commands/mod.rs#L2932)
-
[`insert_resource_if_not_equal_tracks_caller`](https://github.com/micttyoid/bevy/blob/command-insert-resource-if-neq/crates/bevy_ecs/src/system/commands/mod.rs#L2973)

Author: micttyoid

crates/bevy_ecs/src/system/commands/mod.rs

@@ -896,6 +896,22 @@ impl<'w, 's> Commands<'w, 's> {
         self.queue(command::insert_resource(resource));
     }
 
+    /// Inserts a [`Resource`] into the [`World`] with a specific value
+    /// if the resource is different or missing.
+    #[track_caller]
+    pub fn insert_resource_if_neq<R: Resource + PartialEq>(&mut self, resource: R) {
+        let caller = MaybeLocation::caller();
+
+        self.queue(move |world: &mut World| {
+            if world
+                .get_resource::<R>()
+                .is_none_or(|old_resource| *old_resource != resource)
+            {
+                world.insert_resource_with_caller(resource, caller);
+            }
+        });
+    }
+
     /// Removes a [`Resource`] from the [`World`].
     ///
     /// # Example
@@ -2912,6 +2928,111 @@ mod tests {
         assert!(world.contains_resource::<V<f64>>());
     }
 
+    #[test]
+    fn insert_resource_if_not_equal() {
+        #[derive(Resource, PartialEq)]
+        struct P(u8);
+
+        let mut world = World::default();
+        let mut queue = CommandQueue::default();
+
+        {
+            let mut commands = Commands::new(&mut queue, &world);
+            commands.insert_resource_if_neq(P(41));
+        }
+
+        queue.apply(&mut world);
+        assert!(world.is_resource_added::<P>());
+        assert_eq!(world.get_resource::<P>().unwrap().0, 41);
+
+        world.clear_trackers();
+
+        {
+            let mut commands = Commands::new(&mut queue, &world);
+            commands.insert_resource_if_neq(P(42));
+        }
+
+        queue.apply(&mut world);
+        assert!(world.is_resource_changed::<P>());
+        assert_eq!(world.get_resource::<P>().unwrap().0, 42);
+
+        world.clear_trackers();
+
+        {
+            let mut commands = Commands::new(&mut queue, &world);
+            commands.insert_resource_if_neq(P(42));
+        }
+
+        queue.apply(&mut world);
+        assert!(!world.is_resource_changed::<P>());
+        assert_eq!(world.get_resource::<P>().unwrap().0, 42);
+    }
+
+    #[cfg(feature = "track_location")]
+    #[test]
+    fn insert_resource_if_not_equal_tracks_caller() {
+        use crate::change_detection::DetectChanges;
+        use core::panic::Location;
+
+        #[derive(Resource, PartialEq)]
+        struct P(u8);
+
+        let mut world = World::default();
+        let mut queue = CommandQueue::default();
+
+        macro_rules! insert_resource_if_neq_with_expected_caller {
+            ($commands:expr, $resource:expr) => {{
+                $commands.insert_resource_if_neq($resource);
+                Location::caller()
+            }};
+        }
+        let expected1 =
+            insert_resource_if_neq_with_expected_caller!(Commands::new(&mut queue, &world), P(41));
+
+        queue.apply(&mut world);
+
+        assert_eq!(
+            world
+                .get_resource_ref::<P>()
+                .unwrap()
+                .changed_by()
+                .into_option(),
+            Some(expected1)
+        );
+
+        world.clear_trackers();
+
+        let expected2 =
+            insert_resource_if_neq_with_expected_caller!(Commands::new(&mut queue, &world), P(42));
+
+        queue.apply(&mut world);
+
+        assert_eq!(
+            world
+                .get_resource_ref::<P>()
+                .unwrap()
+                .changed_by()
+                .into_option(),
+            Some(expected2)
+        );
+
+        world.clear_trackers();
+
+        let expected3 =
+            insert_resource_if_neq_with_expected_caller!(Commands::new(&mut queue, &world), P(42));
+
+        queue.apply(&mut world);
+
+        assert_ne!(
+            world
+                .get_resource_ref::<P>()
+                .unwrap()
+                .changed_by()
+                .into_option(),
+            Some(expected3)
+        );
+    }
+
     #[test]
     fn remove_component_with_required_components() {
         #[derive(Component)]