Update validation messages for clarity in English and Spanish

- Revised the 'invalid_json' validation message in both English and Spanish to enhance clarity and user understanding. The new messages are more concise and direct, improving the overall user experience when inputting data.

api/resources/lang/en/validation.php

@@ -149,6 +149,6 @@ return [
 
     'attributes' => [],
 
-    'invalid_json' => 'The entered data is invalid JSON. Please correct the data and try again.',
+    'invalid_json' => 'Invalid input. Please correct and try again.',
 
 ];

api/resources/lang/es/validation.php

@@ -152,6 +152,6 @@ return [
         'message' => 'mensaje',
     ],
 
-    'invalid_json' => 'Los datos ingresados no son JSON válido. Por favor, corrija los datos e intente nuevamente.',
+    'invalid_json' => 'Entrada no válida. Por favor, corrija e intente nuevamente.',
 
 ];