Add Electra forks to basic sim tests (#7199)

This PR adds transitions to Electra ~~and Fulu~~ fork epochs in the simulator tests.

~~It also covers blob inclusion verification and data column syncing on a full node in Fulu.~~

UPDATE: Remove fulu fork from sim tests due to https://github.com/sigp/lighthouse/pull/7199#issuecomment-2852281176

testing/node_test_rig/src/lib.rs

@@ -7,7 +7,6 @@ use environment::RuntimeContext;
 use eth2::{reqwest::ClientBuilder, BeaconNodeHttpClient, Timeouts};
 use sensitive_url::SensitiveUrl;
 use std::path::PathBuf;
-use std::sync::Arc;
 use std::time::Duration;
 use std::time::{SystemTime, UNIX_EPOCH};
 use tempfile::{Builder as TempBuilder, TempDir};
@@ -249,7 +248,7 @@ impl<E: EthSpec> LocalExecutionNode<E> {
         if let Err(e) = std::fs::write(jwt_file_path, config.jwt_key.hex_string()) {
             panic!("Failed to write jwt file {}", e);
         }
-        let spec = Arc::new(E::default_spec());
+        let spec = context.eth2_config.spec.clone();
         Self {
             server: MockServer::new_with_config(
                 &context.executor.handle().unwrap(),