test: remove string literals from assert.strictEqual() calls

In test/parallel/test-intl.js, five calls to assert.strictEqual() use a
third, string-literal parameter, which specifies a message to display
when the assertion fails. The problem is that if the assertion fails,
the error message will show the string literal but not the values that
caused the assertion to fail.

This commit removes the third parameter from the five calls and makes
them comments above the assertions instead. The default error message
produced by assert.strictEqual() shows the values that caused the
assertion to fail, which should be somewhat more helpful.

PR-URL: https://github.com/nodejs/node/pull/21211


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>