Fix - Validation errors on default page

[Morsey187]

Description

Link to sample test page: /en/artifacts/x-ray-goggles/
Related PRs/issues: #11646

The changes in this PR aim to solve the following HTML validation errors

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]

Notes on issues not addressed in this PR but highlighted in the validator.

Stray start tag script.

The script tag needs to be inside the body tag.

Initially I thought this was related to the code injecting the widget script, however it's the scripts being injected by the widget script itself, meaning there isn't much we can do this about apart from raise an issue with the provider along the lines of

The following scripts being injected by the widget script should be injected inside the body tag not outside of it.

<script type="text/javascript" async="" src="https://static.fundraiseup.com/401ad27e677a.elementsApi.js"></script>

<script type="text/javascript" async="" src="https://static.fundraiseup.com/checkout.4a5eff42260724f4160e.js"></script>

<script type="text/javascript" async="" src="https://static.fundraiseup.com/checkout-vendors.c58302b7a0e16ce928c0.js"></script>

<script type="text/javascript" async="" src="https://static.fundraiseup.com/checkout-styles.1e7407780ae7ba319eea.js"></script>

However, it's not a huge problem as most issues with HTML validation are related to the intial server side rendered markup sent over the network, this is injected after rendering.

The charset attribute on the script element is obsolete.

I can remove this, however I wouldn’t think there’s much point as we’d only be weakening legacy browser support and we’d still have these same validation errors from scripts injected by a few of the third-party resources.

Unnecessary type attribute

Same as the above around the charset attribute.

I can remove this, however I wouldn’t think there’s much point as we’d only be weakening legacy browser support and we’d still have these same validation errors from scripts injected by a few of the third-party resources.

charset meta element

False positive, issue is with the position of the charset meta element. `<style id="__funBackdropStyles">` is injected above `` so can't do much about this one, however not a major issue as it's not part of the initally rendered markup (I must have copied the markup after the DOM loaded on this one).

Bad value origin-trial for attribute http-equiv

false positive with validator https://github.com/whatwg/html/issues/7858

[mmmavis]

✨ Thanks for addressing these errors @Morsey187