Closes #4943: Delete transients on plugin uninstallation

[Miraeld]

Description

Some transients weren't deleted once the plugin gets uninstalled from a website.

Fixes #4943

Type of change

• Bug fix (non-breaking change which fixes an issue).

Is the solution different from the one proposed during the grooming?

No

Checklists

Generic development checklist

• My code follows the style guidelines of this project, with adapted comments and without new warnings.
• I have added unit and integration tests that prove my fix is effective or that my feature works.
• The CI passes locally with my changes (including unit tests, integration tests, linter).
• Any dependent changes have been merged and published in downstream modules.
• If applicable, I have made corresponding changes to the documentation. Provide a link to the documentation.

Test summary

• I triggered all changed lines of code at least once without new errors/warnings/notices.
• I validated all Acceptance Criteria of the related issues. (If applicable, provide proof).
• I validated all test plan the QA Review asked me to.

[Mai-Saad]

Related test plan https://wpmediaqa.testrail.io/index.php?/runs/view/804&group_by=cases:section_id&group_order=asc&group_id=5010

Note: As per discussion, options are not in the scope of the current PR. Thus wp_rocket_last_base_url is out of scope.

[piotrbak]

@Miraeld @Mai-Saad Based on our conversation today, in order not to make direct deletes from the wp_options table, let's rever the deletion of the dynamic transients.

Thank you @Mai-Saad for bringing this to attention, sorry @Miraeld for changing the requirements.

[Miraeld]

@Mai-Saad There is no need for review again, I've deleted the part that was deleting dynamic transients :)

[Miraeld]

@Mai-Saad , here is the related QA test plan results:
testrail-report-565.pdf

[Mai-Saad]

During the exploratory test of prerelease, these transients won't be deleted after removing wpr
1- while WPML is active
rocket_get_refreshed_fragments_cache_en
if WPML is off
rocket_get_refreshed_fragments_cache
will be deleted.
2- While WPR deleted on multisite, all transients won't be deleted for subsite (network activation was on, same with enable/site)
Agreed that no GH is needed for now.