exclude LakeWriter from test coverage

Author: beryllw

fluss-test-coverage/pom.xml

@@ -445,6 +445,7 @@
                                         <exclude>org.apache.fluss.lake.lance.*</exclude>
                                         <!-- temporarily exclude iceberg -->
                                         <exclude>org.apache.fluss.lake.iceberg.*</exclude>
+                                        <exclude>org.apache.fluss.lake.writer.LakeWriter</exclude>
                                         <exclude>org.apache.fluss.row.encode.iceberg.*</exclude>
                                         <exclude>org.apache.fluss.bucketing.IcebergBucketingFunction</exclude>
                                         <!-- start exclude for flink tiering service -->