opt: allow lookup joins to order on index columns

[cockroach-teamcity]

Exalate commented:

Related PR: cockroachdb/cockroach#84689
Commit: cockroachdb/cockroach@15beca6

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Release note (performance improvement): The optimizer can now return the
results of a join in sorted order in more cases. This can allow the
optimizer to avoid expensive sorts that need to buffer all input rows.

Jira Issue: DOC-5155

[exalate-issue-sync]

Ryan Kuo (taroface) commented:
Closing as this doesn’t require docs IMO.