"On This Page" does not render X^Y^ (X to the power Y) correctly

### Describe the bug

When a header uses the formula in the issue title, for example, 2^32^ (2 to the power 32), the expression is rendered correctly in the section title but not in the OTP. The expression is also rendered correctly in paragraph text.

Example: https://www.elastic.co/docs/explore-analyze/machine-learning/data-frame-analytics/ml-dfa-limitations#dfa-training-docs

### Expected behavior

Render the expression in the OTP the same way as it appears in the paragraph text or the section title.

### Steps to reproduce

_No response_

### Tooling

- [x] docs-builder
- [ ] migration tooling
- [ ] I'm not sure