Remove deprecated CLI flags and references for v8.0.0 (#8142)

Closes #8131

- [x] Remove deprecated flags from beacon_node/src/cli.rs:
- [x] eth1-purge-cache
- [x] eth1-blocks-per-log-query
- [x] eth1-cache-follow-distance
- [x] disable-deposit-contract-sync
- [x] light-client-server
- [x] Remove deprecated flags from lighthouse/src/main.rs:
- [x] logfile
- [x] terminal-total-difficulty-override
- [x] terminal-block-hash-override
- [x] terminal-block-hash-epoch-override
- [x] safe-slots-to-import-optimistically
- [x] Remove references to deprecated flags in config.rs files
- [x] Remove warning messages for deprecated flags in main.rs
- [x] Update/remove related tests in beacon_node.rs


  


Co-Authored-By: Jimmy Chen <jchen.tc@gmail.com>

Co-Authored-By: Jimmy Chen <jimmy@sigmaprime.io>

beacon_node/src/config.rs

@@ -170,13 +170,6 @@ pub fn get_config<E: EthSpec>(
             parse_required(cli_args, "http-duplicate-block-status")?;
     }
 
-    if cli_args.get_flag("light-client-server") {
-        warn!(
-            "The --light-client-server flag is deprecated. The light client server is enabled \
-             by default"
-        );
-    }
-
     if cli_args.get_flag("disable-light-client-server") {
         client_config.chain.enable_light_client_server = false;
     }
@@ -262,24 +255,6 @@ pub fn get_config<E: EthSpec>(
         client_config.http_metrics.allocator_metrics_enabled = false;
     }
 
-    /*
-     * Deprecated Eth1 flags (can be removed in the next minor release after v7.1.0)
-     */
-    if cli_args
-        .get_one::<String>("eth1-blocks-per-log-query")
-        .is_some()
-    {
-        warn!("The eth1-blocks-per-log-query flag is deprecated");
-    }
-
-    if cli_args.get_flag("eth1-purge-cache") {
-        warn!("The eth1-purge-cache flag is deprecated");
-    }
-
-    if clap_utils::parse_optional::<u64>(cli_args, "eth1-cache-follow-distance")?.is_some() {
-        warn!("The eth1-cache-follow-distance flag is deprecated");
-    }
-
     // `--execution-endpoint` is required now.
     let endpoints: String = clap_utils::parse_required(cli_args, "execution-endpoint")?;
     let mut el_config = execution_layer::Config::default();
@@ -773,10 +748,6 @@ pub fn get_config<E: EthSpec>(
         }
     }
 
-    if cli_args.get_flag("disable-deposit-contract-sync") {
-        warn!("The disable-deposit-contract-sync flag is deprecated");
-    }
-
     client_config.chain.prepare_payload_lookahead =
         clap_utils::parse_optional(cli_args, "prepare-payload-lookahead")?
             .map(Duration::from_millis)