util,assert: fix boxed primitives bug

Currently the comparison could throw an error in case a boxed
primitive has no valueOf function on one side of the assert call.

PR-URL: https://github.com/nodejs/node/pull/22243


Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: George Adams <george.adams@uk.ibm.com>