Remove ByteArrayComparer

It's now provided by BSATN.Runtime.

src/Utils.cs

@@ -1,63 +1,6 @@
-using System;
-using System.Collections.Generic;
-using System.Runtime.CompilerServices;
-
-#if !NET5_0_OR_GREATER
+#if !NET5_0_OR_GREATER
 namespace System.Runtime.CompilerServices
 {
-    public static class IsExternalInit { } // https://stackoverflow.com/a/64749403/1484415
+    internal static class IsExternalInit { } // https://stackoverflow.com/a/64749403/1484415
 }
 #endif
-
-namespace SpacetimeDB
-{
-    // Note: this utility struct is used by an autogenerated C# code so it needs to be public.
-    public readonly struct ByteArrayComparer : IEqualityComparer<byte[]>
-    {
-        public static readonly ByteArrayComparer Instance = new();
-
-        public bool Equals(byte[]? left, byte[]? right)
-        {
-            if (ReferenceEquals(left, right))
-            {
-                return true;
-            }
-
-            if (left is null || right is null || left.Length != right.Length)
-            {
-                return false;
-            }
-
-            return EqualsUnvectorized(left, right);
-
-        }
-
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        private static bool EqualsUnvectorized(byte[] left, byte[] right)
-        {
-            for (int i = 0; i < left.Length; i++)
-            {
-                if (left[i] != right[i])
-                {
-                    return false;
-                }
-            }
-
-            return true;
-        }
-
-        public int GetHashCode(byte[] obj)
-        {
-            int hash = 17;
-            foreach (byte b in obj)
-            {
-                hash = hash * 31 + b;
-            }
-            return hash;
-        }
-
-        // Same as `Convert.ToHexString`, but that method is not available in .NET Standard
-        // which we need to target for Unity support.
-        public static string ToHexString(byte[] bytes) => BitConverter.ToString(bytes).Replace("-", "");
-    }
-}