HBASE-26520 Remove use of db.hbase.namespance tracing attribute

The HBase-specific attribute `db.hbase.namespace` has been deprecated in favor of the generic
`db.name`. See also open-telemetry/opentelemetry-specification#1760

Author: ndimiduk

hbase-client/src/main/java/org/apache/hadoop/hbase/client/trace/TableSpanBuilder.java

@@ -19,7 +19,6 @@
 package org.apache.hadoop.hbase.client.trace;
 
 import static org.apache.hadoop.hbase.trace.HBaseSemanticAttributes.DB_NAME;
-import static org.apache.hadoop.hbase.trace.HBaseSemanticAttributes.NAMESPACE_KEY;
 import static org.apache.hadoop.hbase.trace.HBaseSemanticAttributes.TABLE_KEY;
 import io.opentelemetry.api.common.AttributeKey;
 import io.opentelemetry.api.trace.Span;
@@ -81,7 +80,6 @@ static void populateTableNameAttributes(
     final Map<AttributeKey<?>, Object> attributes,
     final TableName tableName
   ) {
-    attributes.put(NAMESPACE_KEY, tableName.getNamespaceAsString());
     attributes.put(DB_NAME, tableName.getNamespaceAsString());
     attributes.put(TABLE_KEY, tableName.getNameAsString());
   }

hbase-client/src/test/java/org/apache/hadoop/hbase/client/trace/hamcrest/TraceTestUtil.java

@@ -47,7 +47,6 @@ public static Matcher<SpanData> buildConnectionAttributesMatcher(AsyncConnection
   public static Matcher<SpanData> buildTableAttributesMatcher(TableName tableName) {
     return hasAttributes(allOf(
       containsEntry("db.name", tableName.getNamespaceAsString()),
-      containsEntry("db.hbase.namespace", tableName.getNamespaceAsString()),
       containsEntry("db.hbase.table", tableName.getNameAsString())));
   }
 }

hbase-common/src/main/java/org/apache/hadoop/hbase/trace/HBaseSemanticAttributes.java

@@ -34,7 +34,6 @@ public final class HBaseSemanticAttributes {
     SemanticAttributes.DB_CONNECTION_STRING;
   public static final AttributeKey<String> DB_USER = SemanticAttributes.DB_USER;
   public static final AttributeKey<String> DB_NAME = SemanticAttributes.DB_NAME;
-  public static final AttributeKey<String> NAMESPACE_KEY = SemanticAttributes.DB_HBASE_NAMESPACE;
   public static final AttributeKey<String> DB_OPERATION = SemanticAttributes.DB_OPERATION;
   public static final AttributeKey<String> TABLE_KEY = AttributeKey.stringKey("db.hbase.table");
   /**