message: chore: clarify helmet changes in changelog
diff: ---
  Updated dependency `helmet` to `^6.0.0`.
  +
  +Please note that these policies are no longer applied by default:
  +
  +helmet.contentSecurityPolicy no longer sets block-all-mixed-content directive by default
  +helmet.expectCt is no longer set by default. It can, however, be explicitly enabled. It will be removed in Helmet 7.
  