Update Mastodon to v2.5.0 | Memory Optimization

[Fraenkiman]

Memory Optimization:

• Switched from monolithic state to split-state normal operation.
• The main state continues to contain global data, entries, reverse indexes, and metadata. However, the large local comment mappings are now stored in shards on a per-entry basis.
• The split-state conversion reduces relevant PHP peak memory usage in normal sync/state operation by approximately 70%. The state.json file becomes about 77% smaller; the total file size increases slightly due to shard metadata. With a PHP memory limit of 128 MB, 3,000×10 is well within safe limits, 10,000×10 is still runnable, and things become critical starting at around 11,000×10.
• The plugin now has its own maintenance page for checking and repairing local plugin state files.