Closes #6474: Update maintenance LCP/ATF

[Miraeld]

Description

Fixes #6474

Documentation

User documentation

This allow to delete old OR failed results from LCP / ATF.

The rocket_atf_cleanup_interval filter is a new feature introduced in this PR. It allows developers to modify the interval at which the Above The Fold (ATF) cleanup process considers a row to be old and therefore eligible for deletion. By default, this interval is set to 1 month. If a row's last_accessed date is more than 1 month ago, it will be deleted during the cleanup process. However, by using this filter, developers can change this interval. For example, if the interval is set to 2 months, then the cleanup process will delete rows where the last_accessed date is more than 2 months ago. Here's an example of how to use this filter:

// Change the ATF cleanup interval to 2 months.
add_filter( 'rocket_atf_cleanup_interval', function() {
    return 2;
});

Technical documentation

• The schedule_atf_cleanup method is used to schedule the 'above the fold' cleanup process to run daily. It checks if the cleanup process is already scheduled using the wp_next_scheduled function. If it's not scheduled, it schedules the event using the wp_schedule_event function.
• The atf_cleanup method is used to execute the 'above the fold' cleanup process. It calls the delete_old_rows method of the ATFTable class to delete the rows with failed status or not accessed since the interval.
• The unschedule_atf_cleanup method is used to unschedule the above the fold cleanup process. It gets the timestamp of the next scheduled cleanup using the wp_next_scheduled function. If a timestamp is found, it unschedules the event using the wp_unschedule_event function

Type of change

Delete options that are not relevant.

• Enhancement (non-breaking change which improves an existing functionality).

New dependencies

Risks

Checklists

Feature validation

• I validated all the Acceptance Criteria. If possible, provide sreenshots or videos.
• I triggered all changed lines of code at least once without new errors/warnings/notices.
• I implemented built-in tests to cover the new/changed code.

Documentation

• I prepared the user documentation for the feature/enhancement and shared it in the PR or the GitHub issue.
• The user documentation covers new/changed entry points (endpoints, WP hooks, configuration files, ...).
• I prepared the technical documentation if needed, and shared it in the PR or the GitHub issue.

Code style

• I wrote self-explanatory code about what it does.
• I wrote comments to explain why it does it.
• I named variables and functions explicitely.
• I protected entry points against unexpected inputs.
• I did not introduce unecessary complexity.
• I listed the introduced external dependencies explicitely on the PR.
• I validated the repo-specific guidelines from CONTRIBUTING.md.

Observability

• I handled errors when needed.
•  I wrote user-facing messages that are understandable and provide actionable feedbacks.

[Mai-Saad]

Related test plan https://wpmediaqa.testrail.io/index.php?/runs/view/845&group_by=cases:section_id&group_id=5031&group_order=asc

For exploratory :

• never cache/always purge with the feature (with never cache, URL won't have lcp nor added to atf on visit. While for always purge, edit URL x will clear only the URL in always Purge from cache but not atf table as in RUCSS) ✔️

[Miraeld]

Here is the related test results:
testrail-report-597.pdf

[MathieuLamiot]

Step 4 of https://wpmediaqa.testrail.io/index.php?/tests/view/41770&group_by=cases:section_id&group_id=5031&group_order=asc worked for me 🤔
For step 3, I don't have the "Clear for this URL" but only "Clear Used CSS" which seem to clear all LCP/ATF.

Probably @wp-media/qa-team can manually run those two steps to confirm for us 😬

[MathieuLamiot]

After discussion with @piotrbak and checking, the test plan is OK for LCP/ATF and failing parts are also failing on trunk:

• clear used CSS for this URL is not available on the editor: Clear Used CSS for this URL does not appear in the post editor #6594
• When using the clear used CSS for this URL in the front-end, the row is deleted instead of being put back to "to submit".