test: fix test-tls-env-extra-ca-file-load

Fixes broken unit test for the NODE_EXTRA_CA_CERTS environment
variable. Unit test was exiting without evaluating any assertions
or running any tests.

Fixes: https://github.com/nodejs/node/issues/32072

PR-URL: https://github.com/nodejs/node/pull/32073


Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>