build: disable -Wattributes warnings on aix

Disable the following compiler warning:

    warning: visibility attribute not supported in this
    configuration; ignored [-Wattributes]

This is gcc complaining about `__attribute((visibility("default"))`
in static library builds. Legitimate but harmless (and uninteresting)
and it drowns out more relevant warnings.

PR-URL: https://github.com/nodejs/node/pull/32419


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>