arc reth: --full only for pruned/minimal; archive keeps full history

Mirror vanilla reth.yml's client_command_dbopts ({{ '- --full' if db_type in
['pruned','minimal'] else '' }}): the arc execution client now omits --full for the
archive variant (full history) and keeps it for pruned/minimal. Previously --full was
hardcoded so both variants ran identical pruned-sync flags.

arc/reth/arc-testnet-reth-archive-trace.yml

@@ -84,7 +84,6 @@ services:
       - --datadir=/data/execution
       - --disable-discovery
       - --enable-arc-rpc
-      - --full
       - --http
       - --http.addr=0.0.0.0
       - --http.api=eth,net,web3,txpool,trace,debug