test: replaces assert.throws() with common.expectsError()

replaces assert.throws() with common.expectsError() to check error code
and error type in parallel/test-buffer-alloc.js

PR-URL: https://github.com/nodejs/node/pull/22689


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>