Redis Cache By Xon 2.18.1

• Fix XF2.3 support for some add-ons depending on extended redis functionality

• Restore XF2.1 support

• Fix high availability support where css updates would be sent to a possible readonly replica instead of the writable instance

• Fix XF2.3 compatibility when css caching is enabled

• XF2.3 compatibility update
  • A bug in XenForo 2.3 Beta 1 (Fixed in beta 2) prevents XenForo from using this as a caching backend without manual code patching references to Adapter\AbstractAdapter to Adapter\AdapterInterface
• Add \SV\RedisCache\Repository\Redis::get()->getRedisConnector() method, this should be used instead of \XF::app()->cache() instanceof Redis or similar.

• Disable behavior which caused css.php to return a 404 on an invalid template.
  For the old behaviour of returning a HTTP 404 response, set this config.php option:
  
  PHP:

  $config['svForce404OnEmptyCss'] = true;

• High avaliability config default change:
  • Change default value for retry_reads_on_primary config option to true as this guards against unexpected replication delays
• Remove unexpected differences for XF2.2 and XF2.3 support (only tested on XF2.2)
• When displaying redis version, include the redis varaint type.
  • Known variants are keydb & dragonflydb.
  • Dragonflydb does not appear to support IO stats at the moment

• Fix helper code to expire/purge redis keys did not support non-main cache backends.
  • If using a separate caching backend for css, old styling was not actively expired as expected, resulting in higher memory usage
  • If 3rd party code uses expireCacheByPattern/purgeCacheByPattern function, the new nullable 'cache' parameter should be used

• Update credis library
• Fix possible php 8.1 compatibility issue

• Display maximum memory and maximum memory policy in admincp redis status information block for troubleshooting purposes