Enforce trailing comma in JS on multiline (#30002)

To keep blame info accurate and to avoid [changes like
this](https://github.com/go-gitea/gitea/pull/29977/files#diff-c3422631a14edbe1e508c4b22f0c718db318be08a6e889427802f9b6165d88d6R359),
it's good to always have a trailing comma, so let's enforce it in JS.

This rule is completely automatically fixable with `make lint-js-fix`
and that's what I did here.

tools/generate-images.js

@@ -20,7 +20,7 @@ async function generate(svg, path, {size, bg}) {
         'removeDimensions',
         {
           name: 'addAttributesToSVGElement',
-          params: {attributes: [{width: size}, {height: size}]}
+          params: {attributes: [{width: size}, {height: size}]},
         },
       ],
     });