11.7.0: Random API improvements

Features

• Implemented string casting for util.UUID instances - @thekid
• Merged PR #327: Use Xoshiro256** (w/o seed) as the fastest engine for
  PHP 8.2+, see https://wiki.php.net/rfc/rng_extension#prng_shootout
  (@thekid)
• Merged PR #326: Deprecate Random::MTRAND as Mersenne Twister is no
  longer recommended, see https://wiki.php.net/rfc/rng_extension
  (@thekid)
• Merged PR #325: Use random_int() instead of mt_rand() in util.UUID
  (@thekid)