Refactor: Added explicit typing and void return types

- Introduced explicit typing to variables and functions across multiple scripts for better code clarity.
- Specified 'void' as the return type for functions that do not return a value.
- Removed redundant code in some scripts.

scenes/scripts/scene_manager.gd

@@ -14,7 +14,7 @@ const SCENES : Dictionary = {
 
 var loading_scene_res : Resource = null
 
-func _ready():
+func _ready() -> void:
 	## LOAD GAME DATA
 	HighScoreMgr.load()
 	HighScoreMgr.debug_output()
@@ -25,7 +25,7 @@ func _ready():
 	SceneMgr.connect("change_scene", Callable(self, "_on_change_scene"))
 	$TransitionScene.connect("transitioned", Callable(self, "_on_transition_scene_transitioned"))
 
-func _on_change_scene(scene_name):
+func _on_change_scene(scene_name : String) -> void:
 	Log.pr("Going to load a scene.", scene_name)
 	if SCENES.has(scene_name):
 		GameState.reset()
@@ -35,6 +35,6 @@ func _on_change_scene(scene_name):
 	else:
 		loading_scene_res = null
 
-func _on_transition_scene_transitioned():
+func _on_transition_scene_transitioned() -> void:
 	$CurrentScene.get_child(0).queue_free()
 	$CurrentScene.add_child(loading_scene_res.instantiate())