Workaround .net error serializing new object()

See https://github.com/dotnet/runtime/issues/61995

src/Readarr.Api.V1/Author/AuthorEditorController.cs

@@ -94,7 +94,7 @@ namespace Readarr.Api.V1.Author
                 _authorService.DeleteAuthor(authorId, false);
             }
 
-            return new object();
+            return new { };
         }
     }
 }

src/Readarr.Api.V1/Blocklist/BlocklistController.cs

@@ -37,7 +37,7 @@ namespace Readarr.Api.V1.Blocklist
         {
             _blocklistService.Delete(resource.Ids);
 
-            return new object();
+            return new { };
         }
     }
 }

src/Readarr.Api.V1/History/HistoryController.cs

@@ -103,7 +103,7 @@ namespace Readarr.Api.V1.History
         public object MarkAsFailed([FromBody] int id)
         {
             _failedDownloadService.MarkAsFailed(id);
-            return new object();
+            return new { };
         }
     }
 }

src/Readarr.Api.V1/ProviderControllerBase.cs

@@ -102,9 +102,10 @@ namespace Readarr.Api.V1
         }
 
         [RestDeleteById]
-        public void DeleteProvider(int id)
+        public object DeleteProvider(int id)
         {
             _providerFactory.Delete(id);
+            return new { };
         }
 
         [HttpGet("schema")]

src/Readarr.Api.V1/Queue/QueueActionController.cs

@@ -31,7 +31,7 @@ namespace Readarr.Api.V1.Queue
 
             _downloadService.DownloadReport(pendingRelease.RemoteBook);
 
-            return new object();
+            return new { };
         }
 
         [HttpPost("grab/bulk")]
@@ -49,7 +49,7 @@ namespace Readarr.Api.V1.Queue
                 _downloadService.DownloadReport(pendingRelease.RemoteBook);
             }
 
-            return new object();
+            return new { };
         }
     }
 }

src/Readarr.Api.V1/Queue/QueueController.cs

@@ -86,7 +86,7 @@ namespace Readarr.Api.V1.Queue
 
             _trackedDownloadService.StopTracking(trackedDownloadIds);
 
-            return new object();
+            return new { };
         }
 
         [HttpGet]