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-svg.js

@@ -39,8 +39,8 @@ async function processFile(file, {prefix, fullName} = {}) {
           attributes: [
             {'xmlns': 'http://www.w3.org/2000/svg'},
             {'width': '16'}, {'height': '16'}, {'aria-hidden': 'true'},
-          ]
-        }
+          ],
+        },
       },
     ],
   });