schemadiff: more `INSTANT` algorithm considerations #901

Job	Run time
Set push variable	1s
Build and push vttestserver (mysql80)	1m 50s
Build and push lite (latest)	2m 8s
Build and push lite (percona80)	2m 7s
Build and push (bullseye, vtadmin)	1m 6s
Build and push (bullseye, vtorc)	31s
Build and push (bullseye, vtgate)	35s
Build and push (bullseye, vttablet)	38s
Build and push (bullseye, mysqlctld)	38s
Build and push (bullseye, mysqlctl)	40s
Build and push (bullseye, vtctl)	32s
Build and push (bullseye, vtctlclient)	32s
Build and push (bullseye, vtctld)	1m 11s
Build and push (bullseye, vtctldclient)	34s
Build and push (bullseye, logrotate)	21s
Build and push (bullseye, logtail)	16s
Build and push (bullseye, vtbackup)	46s
Build and push (bullseye, vtexplain)	34s
Build and push (bookworm, vtadmin)	1m 10s
Build and push (bookworm, vtorc)	24s
Build and push (bookworm, vtgate)	30s
Build and push (bookworm, vttablet)	29s
Build and push (bookworm, mysqlctld)	30s
Build and push (bookworm, mysqlctl)	38s
Build and push (bookworm, vtctl)	36s
Build and push (bookworm, vtctlclient)	48s
Build and push (bookworm, vtctld)	1m 21s
Build and push (bookworm, vtctldclient)	29s
Build and push (bookworm, logrotate)	23s
Build and push (bookworm, logtail)	29s
Build and push (bookworm, vtbackup)	35s
Build and push (bookworm, vtexplain)	26s
	23m 48s

Provide feedback