sql: change physical planning heuristics a bit to prefer local execution

[jseldess]

Jesse Seldess (jseldess) commented:

PR: cockroachdb/cockroach#68524

From release notes:

Some queries with lookup joins and/or top K sorts are now more likely to be executed in "local" manner with the distsql=auto session variable. [#68524][#68524]

Jira Issue: DOC-1385