fix: drop the JsonPointer.Net dependency from the readers

The readers were built against JsonPointer.Net 5.3.1 and used it only to
resolve the fragment of an external reference. JsonPointer.Net 7 removed
JsonPointer.Parse(string), so an app that pulls in 7.x (for example through
JsonSchema.Net 9) hit MissingMethodException when a reference was resolved.
Resolve the fragment with the library's own JsonPointer instead.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: bielu

Directory.Packages.props

@@ -4,7 +4,6 @@
   </PropertyGroup>
 
   <ItemGroup Label="Library">
-    <PackageVersion Include="JsonPointer.Net" Version="5.3.1" />
     <PackageVersion Include="System.Text.Json" Version="9.0.1" />
     <PackageVersion Include="YamlDotNet" Version="13.0.1" />
   </ItemGroup>

src/ByteBard.AsyncAPI.Readers/AsyncApiJsonDocumentReader.cs

@@ -6,12 +6,12 @@ namespace ByteBard.AsyncAPI.Readers
     using System.Text.Json.Nodes;
     using System.Threading;
     using System.Threading.Tasks;
-    using Json.Pointer;
     using ByteBard.AsyncAPI.Exceptions;
     using ByteBard.AsyncAPI.Extensions;
     using ByteBard.AsyncAPI.Models;
     using ByteBard.AsyncAPI.Models.Interfaces;
     using ByteBard.AsyncAPI.Readers.Interface;
+    using ByteBard.AsyncAPI.Readers.ParseNodes;
     using ByteBard.AsyncAPI.Readers.Services;
     using ByteBard.AsyncAPI.Services;
     using ByteBard.AsyncAPI.Validations;
@@ -369,8 +369,8 @@ private IAsyncApiSerializable ResolveStreamReference(Stream stream, IAsyncApiRef
 
             if (reference.Reference.IsFragment)
             {
-                var pointer = JsonPointer.Parse(reference.Reference.FragmentId);
-                if (pointer.TryEvaluate(json, out var pointerResult))
+                var pointerResult = new JsonPointer(reference.Reference.FragmentId).Find(json);
+                if (pointerResult != null)
                 {
                     json = pointerResult;
                 }

src/ByteBard.AsyncAPI.Readers/ByteBard.AsyncAPI.Readers.csproj

@@ -9,7 +9,6 @@
   </PropertyGroup>	
 
   <ItemGroup>
-    <PackageReference Include="JsonPointer.Net" />
     <PackageReference Include="Microsoft.SourceLink.GitHub">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>