You can disable coredump function of systemd by adding this line
For your reference:
Controls where to store cores. One of "none", "external",
"journal", and "both". When "none", the coredumps will be
logged but not stored permanently. When "external" (the
default), cores will be stored in
/var/lib/systemd/coredump. When "journal", cores will be
stored in the journal and rotated following normal
journal rotation patterns. When "both", cores will be
stored in both locations.
When cores are stored in the journal, they might be
compressed following journal compression settings, see
journald.conf(5). When cores are stored externally, they
will be compressed by default, see below.