Update pytensor/scan/rewriting.py

Co-authored-by: Thomas Wiecki <thomas.wiecki@gmail.com>

Author: ricardoV94

pytensor/scan/rewriting.py

@@ -1344,7 +1344,7 @@ def save_mem_new_scan(fgraph, node):
                 else:
                     # there is a **gotcha** here ! Namely, scan returns an
                     # array that contains the initial state of the output
-                    # as well. Which means that if y have a initial state of
+                    # as well. Which means that if y has an initial state of
                     # length 3, and you look for 5 steps you get an output
                     # y of length 8. If you only use y[:5], this does not
                     # mean that you only need to loop for 5 steps but