[REFACTOR] constants / readonly properties

Author: Gonzalo Diaz

src/algorithm_exercises_csharp/hackerrank/interview_preparation_kit/dictionaries_and_hashmaps/FrequencyQueries.cs

@@ -13,14 +13,14 @@ private FrequencyQueries()
     reset();
   }
 
-  private static readonly long __INITIAL__ = 1L;
+  private const long __INITIAL__ = 1L;
 
   private const int __INSERT__ = 1;
   private const int __DELETE__ = 2;
   private const int __SELECT__ = 3;
 
-  private static readonly int __NOT_FOUND__ = 0;
-  private static readonly int __FOUND__ = 1;
+  private const int __NOT_FOUND__ = 0;
+  private const int __FOUND__ = 1;
 
   readonly Dictionary<long, long> valueFreqs = [];
   readonly Dictionary<long, List<long>> freqDictionary = [];