BUG: add function to check whether data is all scalar in pandas.array

Author: antareepsarkar

pandas/_libs/lib.pyx

@@ -865,9 +865,10 @@ cpdef ndarray[object] ensure_string_array(
 def is_all_scalar(obj: list | tuple) -> bool:
     cdef:
         Py_ssize_t i, n = len(obj)
-        bool all_scalars = True
         object temp
 
+    all_scalars = True
+
     for i in range(n):
         temp = obj[i]
         if isinstance(temp, (bytes, str)):