feat: Adds 4 new Reaction delete routes and obsoleting existing routes (#2494)

Octokit.Reactive/Clients/ObservableIssueReactionsClient.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Reactive;
 using System.Reactive.Threading.Tasks;
 using Octokit.Reactive.Internal;
 
@@ -107,5 +108,38 @@ namespace Octokit.Reactive
 
             return _client.Create(repositoryId, number, reaction).ToObservable();
         }
+
+        /// <summary>
+        /// Deletes a reaction for a specified Issue
+        /// </summary>
+        /// <remarks>https://docs.github.com/en/rest/reactions#delete-an-issue-reaction</remarks>
+        /// <param name="owner">The owner of the repository</param>
+        /// <param name="name">The name of the repository</param>
+        /// <param name="issueNumber">The issue number</param>
+        /// <param name="reactionId">The reaction id</param>
+        /// <returns></returns>
+        public IObservable<Unit> Delete(string owner, string name, int issueNumber, int reactionId)
+        {
+            Ensure.ArgumentNotNullOrEmptyString(owner, nameof(owner));
+            Ensure.ArgumentNotNullOrEmptyString(name, nameof(name));
+            Ensure.ArgumentNotNull(reactionId, nameof(reactionId));
+
+            return _client.Delete(owner, name, issueNumber, reactionId).ToObservable();
+        }
+
+        /// <summary>
+        /// Deletes a reaction for a specified Issue
+        /// </summary>
+        /// <remarks>https://docs.github.com/en/rest/reactions#delete-an-issue-reaction</remarks>
+        /// <param name="repositoryId">The owner of the repository</param>
+        /// <param name="issueNumber">The issue number</param>
+        /// <param name="reactionId">The reaction id</param>
+        /// <returns></returns>
+        public IObservable<Unit> Delete(long repositoryId, int issueNumber, int reactionId)
+        {
+            Ensure.ArgumentNotNull(reactionId, nameof(reactionId));
+
+            return _client.Delete(repositoryId, issueNumber, reactionId).ToObservable();
+        }
     }
 }