Remove unused method

Author: nielsbauman

server/src/main/java/org/elasticsearch/cluster/metadata/Metadata.java

@@ -1529,11 +1529,6 @@ public Builder removeIndexTemplate(String name) {
             return this;
         }
 
-        @Deprecated(forRemoval = true)
-        public DataStream dataStream(String dataStreamName) {
-            return getSingleProject().dataStream(dataStreamName);
-        }
-
         @Deprecated(forRemoval = true)
         public Builder dataStreams(Map<String, DataStream> dataStreams, Map<String, DataStreamAlias> dataStreamAliases) {
             getSingleProject().dataStreams(dataStreams, dataStreamAliases);