benchmark: improve assert benchmarks

This reduces the runtime and makes sure the strict and loose options
can be tested individually.

Besides that a couple of redundant cases were removed.

PR-URL: https://github.com/nodejs/node/pull/22211


Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>