9.7.0: Native clone with, PHP 8.5 fixes

• Changed PHP 8.5 emitter to emit clone with expressions natively now
  that the RFC has been implemented
  (@thekid)
• Fixed the warning Using null as an array offset is deprecated, use an
  empty string instead in PHP 8.5+
  (@thekid)
• Fixed the error Arrow functions on the right hand side of |> must be
  parenthesized - see https://externals.io/message/128473#128554
  (@thekid)