[JS] Run less comprehensive every-commit build, relegate multi-target builds perhaps to nightlies

The JavaScript CI build is taking 25-30 minutes nowadays. This could be abbreviated by testing fewer deployment targets. We obviously still need to test all the deployment targets but we could do that nightly instead of on every commit

**Reporter**: [Wes McKinney](https://issues.apache.org/jira/browse/ARROW-6759) / @wesm

_{**Note**: *This issue was originally created as [ARROW-6759](https://issues.apache.org/jira/browse/ARROW-6759). Please see the [migration documentation](https://github.com/apache/arrow/issues/14542) for further details.*}