Jetty embedded web server includes a JNDI initial context when other servers do not

[philwebb]

Currently Jetty embedded web server includes a JNDI initial context when other servers do not. We should align things so that none of our embedded servers create a JNDI context.

See #39840 for an example of the problem a JNDI context can cause.

[philwebb]

We consider this a bug, but too risky to fix in a patch release.