Improves translatability of upsells shown after deleting content

[mhkuu]

Context

• We want to improve the translatability of the upsells that are shown after deleting content that we last touched in this PR. In this PR, we remove the reference "this X" (where X can any content type) and remove the variable that can be either "trashed" or "deleted".

Summary

This PR can be summarized in the following changelog entry:

• Improves translatability of upsells shown after deleting content.

Relevant technical choices:

• Non-user facing as the copy change is super-small.

Test instructions

Test instructions for the acceptance test before the PR gets merged

This PR can be acceptance tested by following these steps:

Delete a post (or any other post type)

• Make sure to have Yoast SEO Premium not installed or deactivated.
• Create and publish a post.
• To your configuration file (wp-config.php), add the following: define( 'EMPTY_TRASH_DAYS', 0 );, or, alternatively, install this plugin.
• Delete this post.
• Make sure that on top the following upsell message is displayed You just deleted a Post. Search engines and other websites can still send traffic to your deleted content. You should create a redirect to ensure your visitors do not get a 404 error when they click on the no longer working URL. With Yoast SEO Premium, you can easily create such redirects..
• Remove define( 'EMPTY_TRASH_DAYS', 0 ); from your config file once more (or delete the plugin added above).

Trash a post (or any other post type)

• Make sure to have Yoast SEO Premium not installed or deactivated.
• Create and publish a post.
• Trash this post.
• Make sure that on top the following upsell message is displayed You just trashed a Post. Search engines and other websites can still send traffic to your trashed content. You should create a redirect to ensure your visitors do not get a 404 error when they click on the no longer working URL. With Yoast SEO Premium, you can easily create such redirects..

Delete a tag (or any other term)

• Make sure to have Yoast SEO Premium not installed or deactivated.
• Create and publish a tag.
• Delete this tag.
• Make sure that on top the following upsell message is displayed You just deleted a Tag. Search engines and other websites can still send traffic to your deleted content. You should create a redirect to ensure your visitors do not get a 404 error when they click on the no longer working URL. With Yoast SEO Premium, you can easily create such redirects..

Relevant test scenarios

• Changes should be tested with the browser console open
• Changes should be tested on different posts/pages/taxonomies/custom post types/custom taxonomies
• Changes should be tested on different editors (Block/Classic/Elementor/other)
• Changes should be tested on different browsers
• Changes should be tested on multisite

Test instructions for QA when the code is in the RC

• QA should use the same steps as above.

QA can test this PR by following these steps:

Impact check

This PR affects the following parts of the plugin, which may require extra testing:

• Upsells after deleting and trashing a post.

UI changes

• This PR changes the UI in the plugin. I have added the 'UI change' label to this PR.

Other environments

• This PR also affects Shopify. I have added a changelog entry starting with [shopify-seo], added test instructions for Shopify and attached the Shopify label to this PR.

Documentation

• I have written documentation for this change.

Quality assurance

• I have tested this code to the best of my abilities.
• During testing, I had activated all plugins that Yoast SEO provides integrations for.
• I have added unit tests to verify the code works as intended.
• If any part of the code is behind a feature flag, my test instructions also cover cases where the feature flag is switched off.
• I have written this PR in accordance with my team's definition of done.
• I have checked that the base branch is correctly set.

Innovation

• No innovation project is applicable for this PR.
• This PR falls under an innovation project. I have attached the innovation label.
• I have added my hours to the WBSO document.

Fixes #20722