fix: set `selector_result_cache_size` in unit test again #19439

Job	Run time
Check (windows-2022)	10m 29s
Build GreptimeDB binaries (ubuntu-20.04)	2m 48s
Check typos and docs	11s
Build GreptimeDB binary (profile-CI) (ubuntu-20.04)	3m 9s
Check (ubuntu-20.04)	2m 5s
Clippy	3m 29s
coverage	14m 34s
Rustfmt	30s
Check License Header	2m 8s
Toml Check	2m 27s
Sqlness Test (Basic)	2m 31s
Sqlness Test (Remote WAL)	2m 44s
Fuzz Test (fuzz_create_table)	7m 19s
Fuzz Test (fuzz_alter_table)	7m 6s
Fuzz Test (fuzz_create_database)	6m 25s
Fuzz Test (fuzz_create_logical_table)	7m 27s
Fuzz Test (fuzz_alter_logical_table)	6m 38s
Fuzz Test (fuzz_insert)	7m 47s
Fuzz Test (fuzz_insert_logical_table)	7m 13s
Unstable Fuzz Test (unstable_fuzz_create_table_standalone)	6m 32s
Fuzz Test with Chaos (Distributed, Remote WAL, fuzz_migrate_mito_regions)	13m 12s
Fuzz Test (Distributed, Remote WAL, fuzz_create_table)	9m 16s
Fuzz Test with Chaos (Distributed, Remote WAL, fuzz_failover_mito_regions)	14m 50s
Fuzz Test (Distributed, Remote WAL, fuzz_alter_table)	11m 8s
Fuzz Test with Chaos (Distributed, Remote WAL, fuzz_failover_metric_regions)	11m 48s
Fuzz Test (Distributed, Remote WAL, fuzz_create_database)	10m 0s
Fuzz Test (Distributed, Remote WAL, fuzz_create_logical_table)	10m 22s
Fuzz Test (Distributed, Remote WAL, fuzz_alter_logical_table)	9m 30s
Fuzz Test (Distributed, Remote WAL, fuzz_insert)	8m 34s
Fuzz Test (Distributed, Remote WAL, fuzz_insert_logical_table)	9m 52s
	3h 32m 4s

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