Fix C lint errors

## C Linting Failures

Linting failures were detected in the automated lint workflow run.

### Workflow Details

- Run: https://github.com/stdlib-js/stdlib/actions/runs/13510451562
- Type: C Linting
- Date: 2025-02-25 00:17:10 UTC

### Error Details

```
lib/node_modules/@stdlib/ndarray/base/assign/src/k_i.c:209:2: style: Variable 'x1' can be declared as pointer to const [constVariablePointer]
STDLIB_NDARRAY_ASSIGN_1D_LOOP_CAST( int16_t, int32_t )
^
lib/node_modules/@stdlib/ndarray/base/assign/src/k_i.c:296:2: style: Variable 'x1' can be declared as pointer to const [constVariablePointer]
STDLIB_NDARRAY_ASSIGN_2D_LOOP_CAST( int16_t, int32_t )
^
lib/node_modules/@stdlib/ndarray/base/assign/src/k_i.c:383:2: style: Variable 'x1' can be declared as pointer to const [constVariablePointer]
STDLIB_NDARRAY_ASSIGN_2D_BLOCKED_LOOP_CAST( int16_t, int32_t )
^
lib/node_modules/@stdlib/ndarray/base/assign/src/k_i.c:470:2: style: Variable 'x1' can be declared as pointer to const [constVariablePointer]
STDLIB_NDARRAY_ASSIGN_3D_LOOP_CAST( int16_t, int32_t )
^
lib/node_modules/@stdlib/ndarray/base/assign/src/k_i.c:557:2: style: Variable 'x1' can be declared as pointer to const [constVariablePointer]
STDLIB_NDARRAY_ASSIGN_3D_BLOCKED_LOOP_CAST( int16_t, int32_t )
^
lib/node_modules/@stdlib/ndarray/base/assign/src/k_i.c:644:2: style: Variable 'x1' can be declared as pointer to const [constVariablePointer]
STDLIB_NDARRAY_ASSIGN_4D_LOOP_CAST( int16_t, int32_t )
^
lib/node_modules/@stdlib/ndarray/base/assign/src/k_i.c:731:2: style: Variable 'x1' can be declared as pointer to const [constVariablePointer]
STDLIB_NDARRAY_ASSIGN_4D_BLOCKED_LOOP_CAST( int16_t, int32_t )
^
lib/node_modules/@stdlib/ndarray/base/assign/src/k_i.c:818:2: style: Variable 'x1' can be declared as pointer to const [constVariablePointer]
STDLIB_NDARRAY_ASSIGN_5D_LOOP_CAST( int16_t, int32_t )
^
lib/node_modules/@stdlib/ndarray/base/assign/src/k_i.c:905:2: style: Variable 'x1' can be declared as pointer to const [constVariablePointer]
STDLIB_NDARRAY_ASSIGN_5D_BLOCKED_LOOP_CAST( int16_t, int32_t )
^
lib/node_modules/@stdlib/ndarray/base/assign/src/k_i.c:992:2: style: Variable 'x1' can be declared as pointer to const [constVariablePointer]
STDLIB_NDARRAY_ASSIGN_6D_LOOP_CAST( int16_t, int32_t )
^
lib/node_modules/@stdlib/ndarray/base/assign/src/k_i.c:1079:2: style: Variable 'x1' can be declared as pointer to const [constVariablePointer]
STDLIB_NDARRAY_ASSIGN_6D_BLOCKED_LOOP_CAST( int16_t, int32_t )
^
lib/node_modules/@stdlib/ndarray/base/assign/src/k_i.c:1166:2: style: Variable 'x1' can be declared as pointer to const [constVariablePointer]
STDLIB_NDARRAY_ASSIGN_7D_LOOP_CAST( int16_t, int32_t )
^
lib/node_modules/@stdlib/ndarray/base/assign/src/k_i.c:1253:2: style: Variable 'x1' can be declared as pointer to const [constVariablePointer]
STDLIB_NDARRAY_ASSIGN_7D_BLOCKED_LOOP_CAST( int16_t, int32_t )
^
lib/node_modules/@stdlib/ndarray/base/assign/src/k_i.c:1340:2: style: Variable 'x1' can be declared as pointer to const [constVariablePointer]
STDLIB_NDARRAY_ASSIGN_8D_LOOP_CAST( int16_t, int32_t )
^
lib/node_modules/@stdlib/ndarray/base/assign/src/k_i.c:1427:2: style: Variable 'x1' can be declared as pointer to const [constVariablePointer]
STDLIB_NDARRAY_ASSIGN_8D_BLOCKED_LOOP_CAST( int16_t, int32_t )
^
lib/node_modules/@stdlib/ndarray/base/assign/src/k_i.c:1514:2: style: Variable 'x1' can be declared as pointer to const [constVariablePointer]
STDLIB_NDARRAY_ASSIGN_9D_LOOP_CAST( int16_t, int32_t )
^
lib/node_modules/@stdlib/ndarray/base/assign/src/k_i.c:1601:2: style: Variable 'x1' can be declared as pointer to const [constVariablePointer]
STDLIB_NDARRAY_ASSIGN_9D_BLOCKED_LOOP_CAST( int16_t, int32_t )
^
lib/node_modules/@stdlib/ndarray/base/assign/src/k_i.c:1688:2: style: Variable 'x1' can be declared as pointer to const [constVariablePointer]
STDLIB_NDARRAY_ASSIGN_10D_LOOP_CAST( int16_t, int32_t )
^
lib/node_modules/@stdlib/ndarray/base/assign/src/k_i.c:1775:2: style: Variable 'x1' can be declared as pointer to const [constVariablePointer]
STDLIB_NDARRAY_ASSIGN_10D_BLOCKED_LOOP_CAST( int16_t, int32_t )
^
lib/node_modules/@stdlib/ndarray/base/assign/src/k_i.c:1862:2: style: Variable 'x1' can be declared as pointer to const [constVariablePointer]
STDLIB_NDARRAY_ASSIGN_ND_LOOP_CAST( int16_t, int32_t )
^
```

Start with lib/node_modules/@stdlib/ndarray/base/assign/src/k_i.c and review the reported macro expansions at the listed lines. Use workflow run 13510451562 to reproduce the C lint check; done means the constVariablePointer warnings no longer appear in the C lint workflow.

Written by the indexing model from the issue text.