Closes #19475: Added timespec to the datetime.isoformat() method.

Added an optional argument timespec to the datetime isoformat() method
to choose the precision of the time component.

Original patch by Alessandro Cucci.
diff --git a/Misc/ACKS b/Misc/ACKS
index 5e6fee7..adc6848 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -309,6 +309,7 @@
 Simon Cross
 Felipe Cruz
 Drew Csillag
+Alessandro Cucci
 Joaquin Cuenca Abela
 John Cugini
 Tom Culliton