test: add test to verify execution parallelism #16

Job	Run time
crdb (c, latest-v22.1, 3.10, newest)	24s
linux (python, 3.7, postgres:10, newest)	7m 43s
crdb (python, latest-v22.2, 3.11)	6m 8s
linux (python, 3.8, postgres:12)	8m 25s
linux (python, 3.9, postgres:13)	8m 33s
macos (python, 3.7)	10m 24s
linux (python, 3.10, postgres:14)	9m 12s
linux (python, 3.11, postgres:15, oldest)	6m 49s
macos (python, 3.8)	8m 39s
linux (c, 3.7, postgres:15, newest)	29s
macos (python, 3.9)	6m 50s
linux (c, 3.8, postgres:13)	24s
macos (python, 3.10)	11m 24s
linux (c, 3.9, postgres:14)	22s
macos (python, 3.11)	5m 54s
linux (c, 3.10, postgres:11, oldest)	45s
macos (c, 3.7)	28s
linux (c, 3.11, postgres:10, newest)	25s
macos (c, 3.8)	24s
linux (python, 3.9, dns, postgres:14)	24s
windows (python, 3.7)	9m 17s
macos (c, 3.9)	24s
linux (python, 3.9, postgis, postgis/postgis)	32s
windows (python, 3.8)	7m 19s
macos (c, 3.10)	25s
windows (python, 3.9)	7m 28s
macos (c, 3.11)	34s
windows (python, 3.10)	9m 45s
windows (python, 3.11)	7m 14s
windows (c, 3.7)	46s
windows (c, 3.8)	41s
windows (c, 3.9)	45s
windows (c, 3.10)	41s
windows (c, 3.11)	47s
	2h 20m 44s

Provide feedback