Put the initialization of LC Store behind the enable-light-client flag (#15464)

* put lc store behind flag

* lint

* remove extra line

beacon-chain/node/node.go

@@ -167,7 +167,6 @@ func New(cliCtx *cli.Context, cancel context.CancelFunc, opts ...Option) (*Beaco
 		syncChecker:             &initialsync.SyncChecker{},
 		custodyInfo:             &peerdas.CustodyInfo{},
 		slasherEnabled:          cliCtx.Bool(flags.SlasherFlag.Name),
-		lcStore:                 &lightclient.Store{},
 	}
 
 	for _, opt := range opts {
@@ -235,6 +234,10 @@ func New(cliCtx *cli.Context, cancel context.CancelFunc, opts ...Option) (*Beaco
 	// their initialization.
 	beacon.finalizedStateAtStartUp = nil
 
+	if features.Get().EnableLightClient {
+		beacon.lcStore = lightclient.NewLightClientStore()
+	}
+
 	return beacon, nil
 }