test: reduce the numbers of databases #9787

Job	Run time
govulncheck	17s
vendorcheck (1.25.5)	21s
b (go1.25.5_2025-12-03, ./tn.sh --unit --enable-race-detection)	7m 4s
b (go1.25.5_2025-12-03, USE_VITESS=true ./tn.sh --integration)	7m 1s
b (go1.25.5_2025-12-03, USE_VITESS=true ./t.sh --start-py)	2m 59s
b (go1.25.5_2025-12-03, ./t.sh --start-py)	3m 1s
b (go1.25.5_2025-12-03, ./t.sh --lints --generate)	2m 54s
b (go1.25.5_2025-12-03, USE_VITESS=true ./t.sh --integration)	5m 53s
b (go1.25.5_2025-12-03, USE_VITESS=true ./tn.sh --unit --enable-race-detection)	7m 11s
b (go1.25.5_2025-12-03, ./t.sh --integration)	5m 50s
b (go1.25.5_2025-12-03, ./tn.sh --integration)	6m 52s
b (go1.25.5_2025-12-03, USE_VITESS=true ./t.sh --unit --enable-race-detection)	6m 45s
b (go1.25.5_2025-12-03, ./t.sh --unit --enable-race-detection)	7m 2s
Boulder CI Test Matrix	2s
	1h 3m 12s

Provide feedback