fdo#75757: remove inheritance to std::vector

Change-Id: I5781799bbd8cc321ff7f659013c6cf68b3253989
Reviewed-on: https://gerrit.libreoffice.org/10868
Reviewed-by: David Tardon <dtardon@redhat.com>
Tested-by: David Tardon <dtardon@redhat.com>