Fix - HTML validation errors on primary pages

[Morsey187]

Description

Link to sample test page: https://foundation.mozilla.org/en/who-we-are/
Related PRs/issues: #11645

Fixes HTML validation errors.
Note the other html validation related PRs solve the majority of the issues for this page so this PR is pretty light, I've noted an issue in a thread which will need to be resolved on production by an editor however.

Checklist

Tests

• Is the code I'm adding covered by tests?

Changes in Models:

• Did I update or add new fake data?
• Did I squash my migration?
• Are my changes backward-compatible. If not, did I schedule a deploy with the rest of the team?

Documentation:

• Is my code documented?
• Did I update the READMEs or wagtail documentation?

Merge Method
💡❗Remember to use squash merge when merging non-feature branches into main

[Morsey187]

Validator flagged this odd error .</span class="body-large"> on the who-we-are page.

Screenshots

Markup

Paragraph within the editor

I couldn't find an issue related to the code investigating this, however I was able to solve it locally by simply reformating the richtext field.
My best guess would be that a user pasted HTML markup directly into the field panel when writing the content for this page, which likely resulted in some formating issues.
I’d recommend someone with access the the wagtail admin on production to should delete the paragraph spacing between

“In the early 2000s, the Mozilla community built Firefox. We toppled the browser monopoly, gave users choice and control online, and helped create a healthier internet.”

and

“Twenty years later, Mozilla continues to fight for a healthy internet — one where Big Tech is held accountable and individual users have real agency
online.”

then apply a new line and republish the page.

[mmmavis]

@Morsey187 thanks for the suggestion on going into the CMS to fix the validation error. I went ahead to make the edit and now the issue is gone!