[chore](beut) fix beut use assume_mutable (#63598)

### What problem does this PR solve?

Related PR: #63386

now use assert_mutable

Author: Mryange

be/benchmark/benchmark_column_array_view.hpp

@@ -126,7 +126,7 @@ static ColumnPtr make_string_array_column() {
 
 // Wrap with outer Nullable (no rows are actually null, just the wrapper overhead).
 static ColumnPtr wrap_nullable(const ColumnPtr& col) {
-    return ColumnNullable::create(col->assume_mutable(),
+    return ColumnNullable::create(col->assert_mutable(),
                                   ColumnUInt8::create(col->size(), 0));
 }
 

be/benchmark/benchmark_column_array_view_distance.hpp

@@ -264,7 +264,7 @@ BENCHMARK(ArrayView_Distance_Const_Plain_Flat)->Unit(benchmark::kNanosecond);
 // ============================================================
 
 static ColumnPtr wrap_nullable_for_dist(const ColumnPtr& col) {
-    return ColumnNullable::create(col->assume_mutable(), ColumnUInt8::create(col->size(), 0));
+    return ColumnNullable::create(col->assert_mutable(), ColumnUInt8::create(col->size(), 0));
 }
 
 static void Handwritten_Distance_Nullable_Plain(benchmark::State& state) {

be/test/core/column/column_array_view_test.cpp

@@ -66,7 +66,8 @@ static ColumnPtr build_int32_array_column(const std::vector<std::vector<int32_t>
         for (auto v : row_nulls) {
             outer_null->insert_value(v);
         }
-        array_col = ColumnNullable::create(array_col->assume_mutable(), std::move(outer_null));
+        ColumnPtr outer_null_col = std::move(outer_null);
+        array_col = ColumnNullable::create(array_col, outer_null_col);
     }
     return array_col;
 }
@@ -101,7 +102,8 @@ static ColumnPtr build_string_array_column(const std::vector<std::vector<std::st
         for (auto v : row_nulls) {
             outer_null->insert_value(v);
         }
-        array_col = ColumnNullable::create(array_col->assume_mutable(), std::move(outer_null));
+        ColumnPtr outer_null_col = std::move(outer_null);
+        array_col = ColumnNullable::create(array_col, outer_null_col);
     }
     return array_col;
 }