Fixed bug in concat uncovered by array API tests

```
import dpctl.tensor as dpt
x1 = dpt.full(tuple(), 77, dtype='u2')
x2 = dpt.zeros(2, dtype='uint8')[dpt.newaxis, :]

dpt.concat((x1, x2), axis=None)
```

The reason the exception was raised is that
_copy_usm_ndarray_for_reshape which is used in the
implementation of concat with axis=None requires
both source and destination to have the same
data-type.

Author: oleksandr-pavlyk

dpctl/tensor/_manipulation_functions.py

@@ -554,8 +554,13 @@ def _concat_axis_None(arrays):
                 sycl_queue=exec_q,
             )
         else:
+            src_ = array
+            # _copy_usm_ndarray_for_reshape requires src and dst to have
+            # the same data type
+            if not array.dtype == res_dtype:
+                src_ = dpt.astype(src_, res_dtype)
             hev, _ = ti._copy_usm_ndarray_for_reshape(
-                src=array,
+                src=src_,
                 dst=res[fill_start:fill_end],
                 shift=0,
                 sycl_queue=exec_q,