Add enable_multi_thread_write as deprecated option

[v01dstar]

enable_multi_thread_write was an option provided in early TiKV versions (5.4 is a known one). A cluster upgrades from early versions to newer versions may encounter [FATAL] [lib.rs:479 ["failed to load_latest_options "Invalid argument: Could not find option: : enable_multi_thread_write""].

Although we load_lastest_options() with ignore_unknown_options=true, the problem still occurs, because ignore_unknown_options is to prevent downgrade compatibility issues, e.g. an option exists in option file that is created by newer versions of RocksDB, but does not exist in the running version. see:

rocksdb/options/options_parser.cc

Lines 288 to 297 in e255444

	// If the option file is not generated by a higher minor version,
	// there shouldn't be any unknown option.
	if (config_options.ignore_unknown_options &&
	section == kOptionSectionVersion) {
	if (db_version[0] < ROCKSDB_MAJOR || (db_version[0] == ROCKSDB_MAJOR &&
	db_version[1] <= ROCKSDB_MINOR)) {
	config_options.ignore_unknown_options = false;
	}
	}

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: LykxSassinator, overvenus

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2025-02-07 01:58:33.539434778 +0000 UTC m=+409785.071846775: ☑️ agreed by LykxSassinator.
• 2025-02-07 03:35:23.751128079 +0000 UTC m=+415595.283540061: ☑️ agreed by overvenus.