chore: add reproduction test for non-deterministic html

Author: Skn0tt

Diff for: packages/python/plotly/plotly/tests/test_io/test_html.py

@@ -38,3 +38,9 @@ def fig1(request):
 
 def test_versioned_cdn_included(fig1):
     assert plotly_cdn_url() in pio.to_html(fig1, include_plotlyjs="cdn")
+
+
+def test_html_deterministic(fig1):
+    assert pio.to_html(fig1, include_plotlyjs="cdn") == pio.to_html(
+        fig1, include_plotlyjs="cdn"
+    )