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.

web_src/js/svg.js

@@ -189,7 +189,7 @@ export const SvgIcon = {
     name: {type: String, required: true},
     size: {type: Number, default: 16},
     className: {type: String, default: ''},
-    symbolId: {type: String}
+    symbolId: {type: String},
   },
   render() {
     let {svgOuter, svgInnerHtml} = svgParseOuterInner(this.name);