Remove leftover templates/CSS files from removed modules/assets from Stable 9

I applied the patch and did lots of searching (grep and find) in core/themes/stable* for the removed modules. Grepping "color" was a bit of fun :-)

I just found one thing that I am not sure about in all the themes stable9 is the only one with a directory and file for ckedito,r core/themes/stable9/css/ckeditor/plugins/language/ckeditor.language.css. Is that needed?

This looks pretty close but I found one more straggler: themes/stable9/templates/admin/color-scheme-form.html.twig is part of Color module.

Should the forum twig files be removed as well? it's still there.

Looks complete to me.

Per @xjm.

Before patch:

[ayrton:stable9 | Wed 11:22:31] $ find . -name '*color*' -ls 
40558237        0 drwxr-xr-x    3 xjm              staff                  96 Sep 14 11:22 ./css/color
40558238        8 -rw-r--r--    1 xjm              staff                3178 Sep 14 11:22 ./css/color/color.admin.css
40558240        0 drwxr-xr-x    5 xjm              staff                 160 Sep 14 11:22 ./images/color
40558245        8 -rw-r--r--    1 xjm              staff                 734 Sep 14 11:22 ./templates/admin/color-scheme-form.html.twig
[ayrton:stable9 | Wed 11:22:32] $ find . -name '*aggregator*' -ls 
40558247        8 -rw-r--r--    1 xjm              staff                1112 Sep 14 11:22 ./templates/dataset/aggregator-feed.html.twig
40558246        8 -rw-r--r--    1 xjm              staff                1023 Sep 14 11:22 ./templates/content/aggregator-item.html.twig
[ayrton:stable9 | Wed 11:22:40] $ find . -name '*rdf*' -ls 
[ayrton:stable9 | Wed 11:23:11] $ find . -name '*ckeditor*' -ls 
40558233        0 drwxr-xr-x    3 xjm              staff                  96 Sep 14 11:22 ./css/ckeditor
40558236        8 -rw-r--r--    1 xjm              staff                 491 Sep 14 11:22 ./css/ckeditor/plugins/language/ckeditor.language.css
[ayrton:stable9 | Wed 11:23:36] $ find . -name '*hal*' -ls 
[ayrton:stable9 | Wed 11:23:52] $ find . -name '*quickedit*' -ls 

After patch:

[ayrton:stable9 | Wed 11:25:52] $ find . -name '*color*' -ls 
[ayrton:stable9 | Wed 11:26:00] $ find . -name '*aggregator*' -ls 
[ayrton:stable9 | Wed 11:26:08] $ find . -name '*rdf*' -ls 
[ayrton:stable9 | Wed 11:26:14] $ find . -name '*ckeditor*' -ls 
[ayrton:stable9 | Wed 11:26:25] $ find . -name '*hal*' -ls 
[ayrton:stable9 | Wed 11:26:30] $ find . -name '*quickedit*' -ls 

Committed to 10.1.x and cherry-picked to 10.0.x. Thanks!

Unless I'm missing something here, sites which are using Stable 9, or a subtheme of it, and also have one of these now-removed modules (or their contrib versions) installed, will be partially broken.

Therefore, this probably means that the modules in question need to re-implement these changes (follow-ups?), but at the very least this should have a change record.

I don't think this will break anything. The Stable and Stable 9 themes were designed so we could update core CSS and templates without breaking backward compatibility. However, in the Drupal 9 cycle we did not update any of the templates that were removed in this patch.

Let's take the case of aggregator-item.html.twig. If someone overrode this in their subtheme of Stable 9, then the overridden version will take precedence now, as it did before. If they did not override it, the template from Stable 9 is now gone, but this will just fall back to the aggregator-item.html.twig template shipped with Aggregator module itself, and the end result will be no different.

I double checked all the templates and CSS removed in this patch and the only difference is in comments and relative paths to assets; there are no structural changes.

Given the above, I am not even sure this needs a change record.

longwave's explanation for why this doesn't need a change record makes sense to me. I updated the API changes section of the issue summary to add that explanation, just in case someone lands on this issue and wonders the same thing.