If a system_uid already exists, update it, otherwise create it
If a system_uid already exists, update it, otherwise create it

Fixes #21067

Previously, we would were reliant on the run_single_worker.rb script to
cleanly exit, and delete it's row.  If that script was terminated abnormally
the row would remain, and the next invocations of the script would create a
new row with the same system_uid value.  This leads to orphaned rows that
cause sync_workers to continually think we're out of sync.

jvlcek/manageiq,skateman/manageiq,skateman/manageiq,jvlcek/manageiq,jrafanie/manageiq,jrafanie/manageiq,NickLaMuro/manageiq,chessbyte/manageiq,mzazrivec/manageiq,NickLaMuro/manageiq,agrare/manageiq,mzazrivec/manageiq,ManageIQ/manageiq,kbrock/manageiq,chessbyte/manageiq,kbrock/manageiq,d-m-u/manageiq,d-m-u/manageiq,ManageIQ/manageiq,NickLaMuro/manageiq,agrare/manageiq,kbrock/manageiq,jvlcek/manageiq,chessbyte/manageiq,jvlcek/manageiq,NickLaMuro/manageiq,mzazrivec/manageiq,ManageIQ/manageiq,mzazrivec/manageiq,jrafanie/manageiq,agrare/manageiq,d-m-u/manageiq,chessbyte/manageiq,agrare/manageiq,skateman/manageiq,skateman/manageiq,d-m-u/manageiq,kbrock/manageiq,jrafanie/manageiq,ManageIQ/manageiq