fix: set `selector_result_cache_size` in unit test (#4631) #19413

Job	Run time
Check typos and docs	8s
Toml Check	38s
Build GreptimeDB binaries (ubuntu-20.04)	2m 43s
Build GreptimeDB binary (profile-CI) (ubuntu-20.04)	3m 20s
Check (windows-2022)	9m 30s
Check (ubuntu-20.04)	2m 18s
Rustfmt	29s
Check License Header	2m 2s
Clippy	3m 43s
coverage	14m 16s
Fuzz Test (fuzz_create_table)	6m 4s
Sqlness Test (Basic)	2m 25s
Fuzz Test (fuzz_alter_table)	6m 41s
Sqlness Test (Remote WAL)	2m 51s
Fuzz Test (fuzz_create_database)	6m 13s
Fuzz Test (fuzz_create_logical_table)	6m 6s
Fuzz Test (fuzz_alter_logical_table)	7m 15s
Fuzz Test (fuzz_insert)	6m 13s
Fuzz Test (fuzz_insert_logical_table)	7m 54s
Unstable Fuzz Test (unstable_fuzz_create_table_standalone)	4m 21s
Fuzz Test with Chaos (Distributed, Remote WAL, fuzz_migrate_mito_regions)	7m 7s
Fuzz Test (Distributed, Remote WAL, fuzz_create_table)	10m 23s
Fuzz Test with Chaos (Distributed, Remote WAL, fuzz_failover_mito_regions)	7m 55s
Fuzz Test (Distributed, Remote WAL, fuzz_alter_table)	10m 2s
Fuzz Test with Chaos (Distributed, Remote WAL, fuzz_failover_metric_regions)	12m 13s
Fuzz Test (Distributed, Remote WAL, fuzz_create_database)	10m 28s
Fuzz Test (Distributed, Remote WAL, fuzz_create_logical_table)	9m 4s
Fuzz Test (Distributed, Remote WAL, fuzz_alter_logical_table)	9m 6s
Fuzz Test (Distributed, Remote WAL, fuzz_insert)	8m 45s
Fuzz Test (Distributed, Remote WAL, fuzz_insert_logical_table)	10m 38s
	3h 10m 51s

Provide feedback