Ignore non-existing table when dropping Iceberg schema with cascade

Author: ebyhr

plugin/trino-iceberg/src/main/java/io/trino/plugin/iceberg/IcebergMetadata.java

@@ -1174,7 +1174,11 @@ public void dropSchema(ConnectorSession session, String schemaName, boolean casc
                 dropView(session, viewName);
             }
             for (SchemaTableName tableName : listTables(session, Optional.of(schemaName))) {
-                dropTable(session, getTableHandle(session, tableName, Optional.empty(), Optional.empty()));
+                ConnectorTableHandle tableHandle = getTableHandle(session, tableName, Optional.empty(), Optional.empty());
+                if (tableHandle != null) {
+                    // getTableHandle method returns null if the table is dropped concurrently
+                    dropTable(session, tableHandle);
+                }
             }
         }
         catalog.dropNamespace(session, schemaName);