chore: Apply suggestions from code review

Author: baywet

src/Microsoft.OpenApi/Models/BaseOpenApiReference.cs

@@ -316,10 +316,10 @@ internal void SetJsonPointerPath(string pointer, string nodeLocation)
         private static string ResolveRelativePointer(string nodeLocation, string relativeRef)
         {
             // Convert nodeLocation to path segments
-            var segments = nodeLocation.TrimStart('#').Split(new char[] {'/'}, StringSplitOptions.RemoveEmptyEntries).ToList();
+            var segments = nodeLocation.TrimStart('#').Split(['/'], StringSplitOptions.RemoveEmptyEntries).ToList();
 
             // Convert relativeRef to dynamic segments
-            var relativeSegments = relativeRef.TrimStart('#').Split(new char[] {'/'}, StringSplitOptions.RemoveEmptyEntries);
+            var relativeSegments = relativeRef.TrimStart('#').Split(['/'], StringSplitOptions.RemoveEmptyEntries);
 
             // Locate the first occurrence of relativeRef segments in the full path
             for (int i = 0; i <= segments.Count - relativeSegments.Length; i++)

src/Microsoft.OpenApi/Models/JsonSchemaReference.cs

@@ -133,7 +133,7 @@ protected override void SetAdditional31MetadataFromMapNode(JsonObject jsonObject
         // Examples
         if (jsonObject.TryGetPropertyValue(OpenApiConstants.Examples, out var examplesNode) && examplesNode is JsonArray examplesArray)
         {
-            Examples = examplesArray.Where(example => example != null).ToList();
+            Examples = examplesArray.OfType<JsonNode>().ToList();
         }
     }
 }