chore: Use .includes and .startsWith, not .indexOf (#7936)

Easier to read than the diverse collection of `=== 0` and `!== -1` and `> -1` tests.

blocks/lists.ts

@@ -227,7 +227,7 @@ const LISTS_CREATE_WITH = {
     // Disconnect any children that don't belong.
     for (let i = 0; i < this.itemCount_; i++) {
       const connection = this.getInput('ADD' + i)!.connection!.targetConnection;
-      if (connection && connections.indexOf(connection) === -1) {
+      if (connection && !connections.includes(connection)) {
         connection.disconnect();
       }
     }