chore: cleanup tech debt in #3696 #15016

Job	Run time
Clippy	2m 14s
Check (windows-latest)	6m 1s
Build GreptimeDB binaries (ubuntu-20.04)	3m 56s
Check (ubuntu-20.04)	1m 34s
coverage	11m 2s
Rustfmt	30s
Toml Check	34s
Spell Check with Typos	15s
Sqlness Test (ubuntu-20.04)	1m 50s
Sqlness Test with Kafka Wal (ubuntu-20.04)	2m 46s
Fuzz Test (fuzz_create_table)	7m 42s
Compatibility Test	40s
Fuzz Test (fuzz_alter_table)	4m 59s
Fuzz Test (fuzz_create_database)	4m 33s
	48m 36s

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