Remove use of OrderedDict in aesara.scan.basic

aesara/scan/basic.py

 import logging
-from collections import OrderedDict
 
 import numpy as np
 
@@ -351,11 +350,11 @@ def scan(
     n_seqs = len(seqs)
     n_outs = len(outs_info)
 
-    return_steps = OrderedDict()
+    return_steps = {}
     # wrap sequences in a dictionary if they are not already dictionaries
     for i in range(n_seqs):
         if not isinstance(seqs[i], dict):
-            seqs[i] = OrderedDict([("input", seqs[i]), ("taps", [0])])
+            seqs[i] = dict([("input", seqs[i]), ("taps", [0])])
         elif seqs[i].get("taps", None) is not None:
             seqs[i]["taps"] = wrap_into_list(seqs[i]["taps"])
         elif seqs[i].get("taps", None) is None:
@@ -377,7 +376,7 @@ def scan(
 
             if not isinstance(outs_info[i], dict):
                 # by default any output has a tap value of -1
-                outs_info[i] = OrderedDict([("initial", outs_info[i]), ("taps", [-1])])
+                outs_info[i] = dict([("initial", outs_info[i]), ("taps", [-1])])
             elif (
                 outs_info[i].get("initial", None) is None
                 and outs_info[i].get("taps", None) is not None
@@ -417,7 +416,7 @@ def scan(
         else:
             # if a None is provided as the output info we replace it
             # with an empty OrdereDict() to simplify handling
-            outs_info[i] = OrderedDict()
+            outs_info[i] = {}
 
     ##
     # Step 2. Generate inputs and outputs of the inner functions
@@ -564,7 +563,7 @@ def scan(
     mit_sot_inner_inputs = []
     mit_sot_inner_slices = []
     mit_sot_inner_outputs = []
-    mit_sot_return_steps = OrderedDict()
+    mit_sot_return_steps = {}
     mit_sot_tap_array = []
     mit_sot_rightOrder = []
 
@@ -573,7 +572,7 @@ def scan(
     sit_sot_inner_inputs = []
     sit_sot_inner_slices = []
     sit_sot_inner_outputs = []
-    sit_sot_return_steps = OrderedDict()
+    sit_sot_return_steps = {}
     sit_sot_rightOrder = []
 
     # go through outputs picking up time slices as needed
@@ -764,9 +763,7 @@ def scan(
     if condition is not None:
         outputs.append(condition)
     fake_nonseqs = [x.type() for x in non_seqs]
-    fake_outputs = clone_replace(
-        outputs, replace=OrderedDict(zip(non_seqs, fake_nonseqs))
-    )
+    fake_outputs = clone_replace(outputs, replace=dict(zip(non_seqs, fake_nonseqs)))
     all_inputs = filter(
         lambda x: (
             isinstance(x, Variable)
@@ -820,7 +817,7 @@ def scan(
         n_outs = len(dummy_outputs)
         if as_while:
             n_outs = n_outs - 1
-        outs_info = [OrderedDict() for x in range(n_outs)]
+        outs_info = [{} for x in range(n_outs)]
 
     # Step 5.1 Outputs with taps different then -1
 
@@ -834,7 +831,7 @@ def scan(
             sit_sot_inner_outputs.append(outputs[i])
 
     # Step 5.3 Outputs that correspond to update rules of shared variables
-    givens = OrderedDict()
+    inner_replacements = {}
     n_shared_outs = 0
     shared_scan_inputs = []
     shared_inner_inputs = []
@@ -843,8 +840,10 @@ def scan(
     for input in dummy_inputs:
         if isinstance(input.variable, SharedVariable) and input.update:
             new_var = safe_new(input.variable)
+
             if getattr(input.variable, "name", None) is not None:
                 new_var.name = input.variable.name + "_copy"
+
             if isinstance(new_var.type, TensorType):
                 sit_sot_inner_inputs.append(new_var)
                 sit_sot_scan_inputs.append(
@@ -864,13 +863,13 @@ def scan(
                 # refers to the update rule with index `-1 - pos`.
                 sit_sot_rightOrder.append(-1 - len(sit_sot_shared))
                 sit_sot_shared.append(input.variable)
-                givens[input.variable] = new_var
+                inner_replacements[input.variable] = new_var
 
             else:
                 shared_inner_inputs.append(new_var)
                 shared_scan_inputs.append(input.variable)
                 shared_inner_outputs.append(input.update)
-                givens[input.variable] = new_var
+                inner_replacements[input.variable] = new_var
                 n_shared_outs += 1
 
     n_sit_sot = len(sit_sot_inner_inputs)
@@ -878,7 +877,7 @@ def scan(
     # Step 5.4 Outputs with no taps used in the input
     n_nit_sot = 0
     nit_sot_inner_outputs = []
-    nit_sot_return_steps = OrderedDict()
+    nit_sot_return_steps = {}
     nit_sot_rightOrder = []
     for i, out in enumerate(outs_info):
         if "taps" not in out:
@@ -905,7 +904,7 @@ def scan(
         if (not isinstance(arg, SharedVariable) and not isinstance(arg, Constant))
     ]
 
-    givens.update(OrderedDict(zip(other_scan_args, other_inner_args)))
+    inner_replacements.update(dict(zip(other_scan_args, other_inner_args)))
 
     if strict:
         non_seqs_set = set(non_sequences if non_sequences is not None else [])
@@ -939,11 +938,13 @@ def scan(
             for arg in dummy_inputs
             if (isinstance(arg.variable, SharedVariable) and not arg.update)
         ]
-    givens.update(OrderedDict(zip(other_shared_scan_args, other_shared_inner_args)))
+    inner_replacements.update(
+        dict(zip(other_shared_scan_args, other_shared_inner_args))
+    )
 
     ##
     # Step 6. Re-order the outputs and clone them replacing things
-    # using the givens
+    # using `inner_replacements`
     ##
     inner_inputs = (
         inner_seqs
@@ -964,10 +965,8 @@ def scan(
     )
     if condition is not None:
         inner_outs.append(condition)
-    # NOTE: legacy code traversed GPU types
-    new_givens = givens
 
-    new_outs = clone_replace(inner_outs, replace=new_givens)
+    new_outs = clone_replace(inner_outs, replace=inner_replacements)
 
     ##
     # Step 7. Create the Scan Op