feat(file_m):allow non-allocatable constructor arg

This commit removes the allocatable attribute from the file_t
constructor function that has a string_t array dummy argument.
Doing so facilitates passing an expression actual argument.

Author: rouson

src/sourcery/sourcery_file_m.f90

@@ -23,7 +23,7 @@ impure elemental module function read_lines(file_name) result(file_object)
 
     pure module function construct(lines) result(file_object)
       implicit none
-      type(string_t), intent(in), allocatable :: lines(:)
+      type(string_t), intent(in) :: lines(:)
       type(file_t) file_object
     end function