[FEAT MERGE] del_tenant_memleak branch

Co-authored-by: HaHaJeff <jeffzhouhhh@gmail.com>

unittest/sql/engine/set/test_hash_set_dump.cpp

@@ -396,7 +396,7 @@ int ObHashSetDumpTest::init_tenant_mgr()
                           ulmt,
                           llmt);
   EXPECT_EQ(OB_SUCCESS, ret);
-  lib::ObTenantCtxAllocator *ctx_allocator =
+  auto ctx_allocator =
     lib::ObMallocAllocator::get_instance()->get_tenant_ctx_allocator(
           OB_SERVER_TENANT_ID, common::ObCtxIds::DEFAULT_CTX_ID);
   EXPECT_EQ(OB_SUCCESS, ret);