chore(deps): bump mermaid from 11.12.3 to 11.15.0

Bumps [mermaid](https://github.com/mermaid-js/mermaid) from 11.12.3 to 11.15.0.
- [Release notes](https://github.com/mermaid-js/mermaid/releases)
- [Commits](https://github.com/mermaid-js/mermaid/compare/mermaid@11.12.3...mermaid@11.15.0)

---
updated-dependencies:
- dependency-name: mermaid
  dependency-version: 11.15.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

package.json

@@ -84,7 +84,7 @@
     "mdast-util-to-markdown": "^2.1.2",
     "mdast-util-to-string": "^4.0.0",
     "mdx-bundler": "^10.0.1",
-    "mermaid": "^11.11.0",
+    "mermaid": "^11.15.0",
     "micromark": "^4.0.0",
     "next": "^15.5.18",
     "next-plausible": "^3.12.4",