Avoid skipping channels in pulse visualizer (#8974)

* Modify pulse visualizer test to fail due to missing channel

Reproduces #8981

* Avoid skipping channels in pulse visualizer

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

qiskit/visualization/pulse_v2/layouts.py

@@ -178,7 +178,7 @@ def channel_index_grouped_sort(
 
     ordered_channels = []
 
-    for ind in inds:
+    for ind in sorted(inds):
         # drive channel
         if len(d_chans) > 0 and d_chans[-1].index == ind:
             ordered_channels.append(d_chans.pop())
@@ -241,7 +241,7 @@ def channel_index_grouped_sort_u(
 
     ordered_channels = []
 
-    for ind in inds:
+    for ind in sorted(inds):
         # drive channel
         if len(d_chans) > 0 and d_chans[-1].index == ind:
             ordered_channels.append(d_chans.pop())

releasenotes/notes/visualization-missing-channels-bc66c1c976a79c06.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    Fixed an issue where in some cases pulse visualization would omit some of
+    the channels in a schedule. Fixed #8981.

test/python/visualization/pulse_v2/test_layouts.py

@@ -108,6 +108,9 @@ def test_channel_type_grouped_sort(self):
 
     def test_channel_index_sort(self):
         """Test channel_index_grouped_sort."""
+        # Add an unusual channel number to stress test the channel ordering
+        self.channels.append(pulse.DriveChannel(100))
+        self.channels.reverse()
         out_layout = layouts.channel_index_grouped_sort(
             self.channels, formatter=self.formatter, device=self.device
         )
@@ -123,9 +126,10 @@ def test_channel_index_sort(self):
             [pulse.MeasureChannel(2)],
             [pulse.AcquireChannel(2)],
             [pulse.ControlChannel(5)],
+            [pulse.DriveChannel(100)],
         ]
 
-        ref_names = ["D0", "U0", "D1", "M1", "A1", "D2", "U2", "M2", "A2", "U5"]
+        ref_names = ["D0", "U0", "D1", "M1", "A1", "D2", "U2", "M2", "A2", "U5", "D100"]
 
         ref = list(zip(ref_names, ref_channels))