build: remove suppressions.supp

We have removed the UBSan workflow
and there's no ongoing initiative to
bring it back.

PR-URL: nodejs#59079
Reviewed-By: Richard Lau <richard.lau@ibm.com>
Reviewed-By: Marco Ippolito <marcoippolito54@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

Author: RafaelGSS