fix: unconsistent visibility of properties in current keys class

Author: baywet

src/Microsoft.OpenApi/Services/OpenApiWalker.cs

@@ -1279,32 +1279,32 @@ public class CurrentKeys
         /// <summary>
         /// Current Path key
         /// </summary>
-        public string? Path { get; set; }
+        public string? Path { get; internal set; }
 
         /// <summary>
         /// Current Operation Type
         /// </summary>
-        public HttpMethod? Operation { get; set; }
+        public HttpMethod? Operation { get; internal set; }
 
         /// <summary>
         /// Current Response Status Code
         /// </summary>
-        public string? Response { get; set; }
+        public string? Response { get; internal set; }
 
         /// <summary>
         /// Current Content Media Type
         /// </summary>
-        public string? Content { get; set; }
+        public string? Content { get; internal set; }
 
         /// <summary>
         /// Current Callback Key
         /// </summary>
-        public string? Callback { get; set; }
+        public string? Callback { get; internal set; }
 
         /// <summary>
         /// Current Link Key
         /// </summary>
-        public string? Link { get; set; }
+        public string? Link { get; internal set; }
 
         /// <summary>
         /// Current Header Key

test/Microsoft.OpenApi.Tests/PublicApi/PublicApi.approved.txt

@@ -60,16 +60,16 @@ namespace Microsoft.OpenApi
     public class CurrentKeys
     {
         public CurrentKeys() { }
-        public string? Callback { get; set; }
-        public string? Content { get; set; }
+        public string? Callback { get; }
+        public string? Content { get; }
         public string? Encoding { get; }
         public string? Example { get; }
         public string? Extension { get; }
         public string? Header { get; }
-        public string? Link { get; set; }
-        public System.Net.Http.HttpMethod? Operation { get; set; }
-        public string? Path { get; set; }
-        public string? Response { get; set; }
+        public string? Link { get; }
+        public System.Net.Http.HttpMethod? Operation { get; }
+        public string? Path { get; }
+        public string? Response { get; }
         public string? ServerVariable { get; }
     }
     [System.AttributeUsage(System.AttributeTargets.Property | System.AttributeTargets.Field)]