webpack fails with mermaid 9.4.3 on bullseye, and 9.1.6 is known to work

--- a/package.json
+++ b/package.json
@@ -151,7 +151,7 @@
     "marked": "^4.0.18",
     "mathjax": "3",
     "mdurl": "^1.0.1",
-    "mermaid": "^9.1.3",
+    "mermaid": "9.1.6",
     "micromatch": "^4.0.5",
     "minimatch": "^3.0.4",
     "monaco-editor": "^0.30.1",