Remove deprecated flags for v7 release (#15986)

* Delete deprecated flags

* Changelog fragment

* E2E: Remove delete flag usage.

---------

Co-authored-by: Manu NALEPA <enalepa@offchainlabs.com>

testing/endtoend/component_handler_test.go

@@ -136,10 +136,6 @@ func (c *componentHandler) setup() {
 	})
 	c.eth1Nodes = eth1Nodes
 
-	if config.TestCheckpointSync {
-		appendDebugEndpoints(config)
-	}
-
 	var builders *components.BuilderSet
 	var proxies *eth1.ProxySet
 	if config.UseBuilder {
@@ -290,10 +286,3 @@ func PIDsFromMultiComponentRunner(runner e2etypes.MultipleComponentRunners) []in
 	}
 	return pids
 }
-
-func appendDebugEndpoints(cfg *e2etypes.E2EConfig) {
-	debug := []string{
-		"--enable-debug-rpc-endpoints",
-	}
-	cfg.BeaconFlags = append(cfg.BeaconFlags, debug...)
-}