build: for --enable-static, run only cctest

Currently when building with --enable-static and running the test target
the following error will be reported:
Building addon
/node/test/addons/01_function_arguments/
env: ./node: No such file or directory
make[1]: *** [test/addons/.buildstamp] Error 1

Note that this is with a clean build where no prior node executable was
built.

This commit suggests only running the cctest target when --enable-static
is specified.

PR-URL: https://github.com/nodejs/node/pull/14892


Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Lance Ball <lball@redhat.com>