[Refactor] remove unnecessary condition

`canHaveTrailingComma` is defined as `I(lastElem && ...)`, which will always be true when `lastElem === null`.

src/language-js/printer-estree.js

@@ -1518,8 +1518,7 @@ function printPathNoParens(path, options, print, args) {
         //
         // Note that getLast returns null if the array is empty, but
         // we already check for an empty array just above so we are safe
-        const needsForcedTrailingComma =
-          canHaveTrailingComma && lastElem === null;
+        const needsForcedTrailingComma = lastElem === null;
 
         parts.push(
           group(