Remove warning comments (#5730)

## Description
Removes comments added in #5704. The change setting None cases to true
is actually correct and what we want. @danielbate

Author: JoshuaBatty

sway-core/src/decl_engine/engine.rs

@@ -190,23 +190,15 @@ macro_rules! decl_engine_clear_module {
                 self.parents.write().unwrap().retain(|key, _| {
                     match key {
                         AssociatedItemDeclId::TraitFn(decl_id) => {
-                            // WARNING: Setting to true disables garbage collection for these cases.
-                            // This should be set back to false once this issue is solved: https://github.com/FuelLabs/sway/issues/5698
                             self.get_trait_fn(decl_id).span().source_id().map_or(true, |src_id| &src_id.module_id() != module_id)
                         },
                         AssociatedItemDeclId::Function(decl_id) => {
-                            // WARNING: Setting to true disables garbage collection for these cases.
-                            // This should be set back to false once this issue is solved: https://github.com/FuelLabs/sway/issues/5698
                             self.get_function(decl_id).span().source_id().map_or(true, |src_id| &src_id.module_id() != module_id)
                         },
                         AssociatedItemDeclId::Type(decl_id) => {
-                            // WARNING: Setting to true disables garbage collection for these cases.
-                            // This should be set back to false once this issue is solved: https://github.com/FuelLabs/sway/issues/5698
                             self.get_type(decl_id).span().source_id().map_or(true, |src_id| &src_id.module_id() != module_id)
                         },
                         AssociatedItemDeclId::Constant(decl_id) => {
-                            // WARNING: Setting to true disables garbage collection for these cases.
-                            // This should be set back to false once this issue is solved: https://github.com/FuelLabs/sway/issues/5698
                             self.get_constant(decl_id).span().source_id().map_or(true, |src_id| &src_id.module_id() != module_id)
                         },
                     }
@@ -215,8 +207,6 @@ macro_rules! decl_engine_clear_module {
                 $(
                     self.$slab.retain(|_k, ty| match ty.span().source_id() {
                         Some(source_id) => &source_id.module_id() != module_id,
-                        // WARNING: Setting to true disables garbage collection for these cases.
-                        // This should be set back to false once this issue is solved: https://github.com/FuelLabs/sway/issues/5698
                         None => true,
                     });
                 )*

sway-core/src/decl_engine/parsed_engine.rs

@@ -142,8 +142,6 @@ macro_rules! decl_engine_clear_module {
                         let span = $getter(item);
                         match span.source_id() {
                             Some(source_id) => &source_id.module_id() != module_id,
-                            // WARNING: Setting to true disables garbage collection for these cases.
-                            // This should be set back to false once this issue is solved: https://github.com/FuelLabs/sway/issues/5698
                             None => true,
                         }
                     });

sway-core/src/type_system/engine.rs

@@ -72,17 +72,13 @@ impl TypeEngine {
     pub fn clear_module(&mut self, module_id: &ModuleId) {
         self.slab.retain(|_, tsi| match tsi.source_id {
             Some(source_id) => &source_id.module_id() != module_id,
-            // WARNING: Setting to true disables garbage collection for these cases.
-            // This should be set back to false once this issue is solved: https://github.com/FuelLabs/sway/issues/5698
             None => true,
         });
         self.id_map
             .write()
             .unwrap()
             .retain(|tsi, _| match tsi.source_id {
                 Some(source_id) => &source_id.module_id() != module_id,
-                // WARNING: Setting to true disables garbage collection for these cases.
-                // This should be set back to false once this issue is solved: https://github.com/FuelLabs/sway/issues/5698
                 None => true,
             });
     }