3.18 - Front-end display - Duplicated tag added to the page

[Miraeld]

Describe the bug

When we are enabling the Host Google Font, we are getting a duplicated tag in the HTML.

To Reproduce

1. Move yourself to the branch feature/7063-google-font-front-end from Closes #7063: Google font - Frontend part #7091
2. Enable Host Google Font in WPR settings under the Media tab.
3. Load a page with a google font,
4. Check the HTML of the page.

For example, if on my page I get
<link href="https://fonts.googleapis.com/css?family=Roboto" rel="stylesheet">
As an output I'll get the following:

<link rel="stylesheet" href="http://localhost:8902/wp-content/cache/fonts/1/6/a/5/45cf0dd85cb9d27a7fcae31c68aee.css" data-wpr-hosted-gf-parameters="family=Roboto&amp;">
<link rel="stylesheet" href="http://localhost:8902/wp-content/cache/fonts/1/6/a/5/45cf0dd85cb9d27a7fcae31c68aee.css" data-wpr-hosted-gf-parameters="family=Roboto&amp;">

Expected behavior

We should have only one tag added.

Additional context

To get more understanding of the issue, this is happening before the Google Font Combination is happening before our new feature. This way, we don't have to duplicate the combination of google font. That's the easiest way to do and this is what we did.

However, in here:

wp-rocket/inc/Engine/Optimization/GoogleFonts/AbstractGFOptimization.php

Line 113 in 7348869

protected function get_optimized_markup( string $url ): string {

We are adding the rel="preload" tag that is annoying us.

If the rel="preload" isn't necessary while we are hosting the font css locally, we could add a check wether the new feature is enabled or not, depending on this, we could add the preload tag or not.

[Miraeld]

Scope a solution

As mentioned in the Additional Context of the issue, we need to avoid adding the preload tag in here
if the newly added feature is enabled (host_fonts_locally).