Footnotes Do Not Appear In Search Results

### Quick summary

The search results (using the Search Block) on a site do not show results from Footnotes.
From sample page:

From search results:

### Steps to reproduce

1. Add a Footnotes block to any post or page, and add text with a unique word or phrase
2. If necessary, add Search block to the site
3. Search for the unique word set in Footnotes

### What you expected to happen

Post or page with the relevant Footnotes will appear in the Search results

### What actually happened

The post or page with the footnote does not appear in search results.

### Impact

Most (> 50%)

### Available workarounds?

No but the platform is still usable

### Platform (Simple and/or Atomic)

_No response_

### Logs or notes

_No response_

Reproduce the issue with a Footnotes block and a Search block using a unique phrase, then trace the Search block and Footnotes block handling in wp-calypso. Check how footnote text is represented in search results. Done means the post or page containing the unique footnote text appears in the site's search results.

Written by the indexing model from the issue text.