Fix Attachment integration test

Appears that detect language is required in the 5.0.0-alpha1 compatible version of the plugin in order to be able to query on explicit language

Author: russcam

src/Tests/Document/Single/Attachment/AttachmentApiTests.cs

@@ -199,7 +199,8 @@ public class AttachmentExplicitWithMetadataApiTests : AttachmentApiTestsBase
 					ContentType = "application/pdf",
 					Content = Content,
 					Name = "content name",
-					Language = "en"
+					Language = "en",
+					DetectLanguage = true
 				}
 			};
 
@@ -215,7 +216,8 @@ public AttachmentExplicitWithMetadataApiTests(IndexingCluster cluster, EndpointU
 					_content = Content,
 					_content_type = "application/pdf",
 					_name = "content name",
-					_language = "en"
+					_language = "en",
+					_detect_language = true
 				}
 			};