Bump rocksdb to 8.5.4

[aleksraiden]

Bump RocksDB to 8.5 mainline.

A key features (incl. 8.4 release):

• Fixed bugs in sub-compactions and deleting old data
• Fix possible data corruption
• A lot of bugs in io_ring/async_io support (important for 6.0+ linux kernel users) - very important for performance
• Fix race conditions in rate limiters

Other notable changes:

• Option periodic_compaction_seconds no longer supports FIFO compaction
• Stop exposing a general-purpose cache interface
• Add new metrics
• Change the default value for option level_compaction_dynamic_level_bytes to true (we are already use it)

Full changelog with detailed info - https://github.com/facebook/rocksdb/releases/tag/v8.5.4

[torwig]

Since a lot of bugs were fixed in this version, LGTM.