fix: allow trailing commas on biome.jsonc

[yukulele]

Summary

vscode reports trailing commas as error in biome.jsonc

Test Plan

try to use this file on vscode:

// biome.jsonc
{
  "$schema": "./node_modules/@biomejs/biome/configuration_schema.json",
  "json": {
    "formatter": {
      "trailingCommas": "all",
    },
  },
}

adding "allowTrailingCommas": true to configuration_schema.json fix it

[ematipico]

This file is auto-generated, we need to change the source code that generates it.

[ematipico]

Closing, JSON schema doesn't have a allowTrailingCommas keyword