fix: update to work with mpl3.8

Author: andrzejnovak

src/mplhep/plot.py

@@ -1074,8 +1074,8 @@ def __init__(self, xsizes, ysizes, divider):
         self.div = divider
 
     def get_size(self, renderer):
-        xrel, xabs = axes_size.AddList(self.xsizes).get_size(renderer)
-        yrel, yabs = axes_size.AddList(self.ysizes).get_size(renderer)
+        xrel, xabs = sum(self.xsizes, start=axes_size.Fixed(0)).get_size(renderer)
+        yrel, yabs = sum(self.ysizes, start=axes_size.Fixed(0)).get_size(renderer)
         bb = Bbox.from_bounds(*self.div.get_position()).transformed(
             self.div._fig.transFigure
         )

tests/baseline/test_square_cbar.png

@@ -0,0 +1,27 @@
+from __future__ import annotations
+
+import os
+
+import matplotlib.pyplot as plt
+import pytest
+
+os.environ["RUNNING_PYTEST"] = "true"
+
+import mplhep as hep  # noqa: E402
+
+"""
+To test run:
+python pytest -r sa --mpl --mpl-results-path=pytest_results
+
+When adding new tests, run:
+python pytest -r sa --mpl --mpl-generate-path=tests/baseline
+"""
+
+plt.switch_backend("Agg")
+
+
+@pytest.mark.mpl_image_compare(style="default", remove_text=True)
+def test_square_cbar():
+    fig, ax = plt.subplots()
+    ax = hep.make_square_add_cbar(ax=ax)
+    return fig