Downgrade some unnecessary loggings

Enhancement

Downgrade from "error" to "info"

[2026/01/04 10:28:24.366 +00:00] [ERROR] [command.rs:187] ["transfer leader won't exec"] [req="cmd_type: TransferLeader transfer_leader { peer { id: 19010003 store_id: 96 role: IncomingVoter } }"] [region="id: 13472243 start_key: ? end_key: ? region_epoch { conf_ver: 145 version: 521 } peers { id: 13472244 store_id: 36 role: Learner } peers { id: 13472246 store_id: 35 role: Learner } peers { id: 13473633 store_id: 11 } peers { id: 13473631 store_id: 12 role: Learner } peers { id: 13473630 store_id: 39 } peers { id: 13473632 store_id: 94 role: DemotingVoter } peers { id: 19010003 store_id: 96 role: IncomingVoter }"] [thread_id=418]

https://github.com/pingcap/tidb-engine-ext/blob/768e3440b32dafe94d326b298e64a1165ea7ec0e/proxy_components/engine_store_ffi/src/core/forward_raft/command.rs#L187-L190

Downgrade from "warn" to "info"

when extra_suffix is '00'

[2026/01/04 09:59:25.592 +00:00] [WARN] [RowKeyRangeFromRegion.cpp:110] ["Meet rowkey which has extra suffix, keyspace=4294967295 table_id=488920  end_key=? end_key_extra_suffix=00 region_id=38012807 getQueryRanges"] [thread_id=8831]

when meet empty schema diff

[2026/01/04 10:28:18.161 +00:00] [WARN] [SchemaGetter.cpp:254] ["The schema diff is empty, schema_version=73978 key=Diff:73978"] [thread_id=8182]
[2026/01/04 08:22:27.828 +00:00] [WARN] [TiDBSchemaSyncer.cpp:164] ["Skip an empty schema diff, schema_version=45172 cur_version=45171 latest_version=45173"] [source="keyspace=4294967295"] [thread_id=7934]

Start by reading the logging sites in engine_store_ffi/src/core/forward_raft/command.rs around lines 187-190, RowKeyRangeFromRegion.cpp:110, SchemaGetter.cpp:254, and TiDBSchemaSyncer.cpp:164. Verify each listed condition and change only the specified error or warning severity to info; done means these expected conditions no longer emit error or warn logs.