fix(l1): fix tooling/sync sync target so it uses existing target

[cdiielsi]

Motivation

When running make sync in tooling/sync you get the following error:

make start-ethrex-hoodi >> ./logs/ethrex-sync-hoodi-levm.log
make[1]: *** No rule to make target `start-ethrex-hoodi'.  Stop.
make: *** [sync] Error 2

Because the specific start-ethrex-hoodi target no longer exists since this pr.

Description

Change start-ethrex-$(NETWORK) to start-ethrex in sync target as it was intended to be used since pr