Delete deprecated cli flags (#4906)

* Delete BN spec flag and VC beacon-node flag

* Remove warn

* slog

* add warn

* delete eth1-endpoint

* delete server from vc cli.rs

* delete server flag in config.rs

* delete delete-lockfiles in vc

* delete allow-unsynced flag in VC

* delete strict-fee-recipient in VC and warn log

* delete merge flag in bn (hidden)

* delete count-unrealized and count-unrealized-full in bn (hidden)

* delete http-disable-legacy-spec in bn (hidden)

* delete eth1-endpoint in lcli

* delete warn message lcli

* delete eth1-endpoints

* delete minify in slashing protection

* delete minify related

* Remove mut

* add back warn! log

* Indentation

* Delete count-unrealized

* Delete eth1-endpoints

* Delete eth1-endpoint test

* delete eth1-endpints test

* delete allow-unsynced test

* Add back lcli eth1-endpoint

---------

Co-authored-by: Michael Sproul <michael@sigmaprime.io>

lighthouse/tests/validator_client.rs

@@ -101,12 +101,6 @@ fn beacon_nodes_flag() {
         });
 }
 
-#[test]
-fn allow_unsynced_flag() {
-    // No-op, but doesn't crash.
-    CommandLineTest::new().flag("allow-unsynced", None).run();
-}
-
 #[test]
 fn disable_auto_discover_flag() {
     CommandLineTest::new()