fixup! Added missing include for github pipeline

Author: GiovaGa

include/graphblas/nonblocking/coordinates.hpp

@@ -35,6 +35,7 @@
 
 #include <stddef.h> //size_t
 #include <assert.h>
+#include <cstdint> // uintptr_t
 
 #include <graphblas/rc.hpp>
 #include <graphblas/backends.hpp>

include/graphblas/reference/coordinates.hpp

@@ -29,6 +29,7 @@
 
 #include <assert.h>
 #include <string.h> //memcpy
+#include <cstdint> // uintptr_t
 
 #include <graphblas/backends.hpp>
 #include <graphblas/base/coordinates.hpp>