fix --ci-mode benchmarks

--ci-mode was stopping after warmup builds

Bug: 297449147
Test: try --ci-mode
Change-Id: Ie355356053d96c75844beb0eee4ce8923753139e
diff --git a/scripts/incremental_build/cuj_catalog.py b/scripts/incremental_build/cuj_catalog.py
index 5c8eb83..26866fc 100644
--- a/scripts/incremental_build/cuj_catalog.py
+++ b/scripts/incremental_build/cuj_catalog.py
@@ -19,13 +19,11 @@
 import tempfile
 import uuid
 from pathlib import Path
-from typing import Callable, Final
-from typing import Optional
+from typing import Callable, Final, Optional
 
 import clone
 import cuj
 import finder
-import ui
 import util
 import random
 import re
@@ -44,14 +42,6 @@
 """
 
 
-class Warmup(CujGroup):
-    def __init__(self):
-        super().__init__("WARMUP")
-
-    def get_steps(self) -> list[CujStep]:
-        return [CujStep("", lambda: None)]
-
-
 class Clean(CujGroup):
     def __init__(self):
         super().__init__("clean")
@@ -64,10 +54,16 @@
         return [CujStep("", clean)]
 
 
-class NoChange(Warmup):
+class NoChange(CujGroup):
     def __init__(self):
-        super().__init__()
-        self._desc = "no change"
+        super().__init__("no change")
+
+    def get_steps(self) -> list[CujStep]:
+        return [CujStep("", lambda: None)]
+
+
+Warmup: Final[CujGroup] = NoChange()
+Warmup._desc = "WARMUP"
 
 
 class Modify(CujGroup):
diff --git a/scripts/incremental_build/incremental_build.py b/scripts/incremental_build/incremental_build.py
index e9f4591..5203ca0 100644
--- a/scripts/incremental_build/incremental_build.py
+++ b/scripts/incremental_build/incremental_build.py
@@ -347,7 +347,7 @@
         util.CURRENT_BUILD_TYPE = build_type
         # warm-up run reduces variations attributable to OS caches
         if user_input.chosen_cujgroups and not user_input.no_warmup:
-            run_cuj_group(cuj_catalog.Warmup())
+            run_cuj_group(cuj_catalog.Warmup)
         for i in user_input.chosen_cujgroups:
             run_cuj_group(cuj_catalog.get_cujgroups()[i])
     _display(r"^(?:time|bp2build|soong_build/\*\.bazel)$")