fix: make besu a bootnode (#146)

Changelog picked up from commits here:

fix: make besu a bootnode

src/package_io/parse_input.star

@@ -14,7 +14,6 @@ DEFAULT_CL_IMAGES = {
 	"lodestar":		"chainsafe/lodestar:latest",
 }
 
-BESU_NODE_NAME = "besu"
 NETHERMIND_NODE_NAME = "nethermind"
 NIMBUS_NODE_NAME = "nimbus"
 
@@ -58,9 +57,6 @@ def parse_input(input_args):
 		el_client_type = participant["el_client_type"]
 		cl_client_type = participant["cl_client_type"]
 
-		if index == 0 and el_client_type in (BESU_NODE_NAME):
-			fail("besu cant be the first participant")
-
 		if cl_client_type in (NIMBUS_NODE_NAME) and (result["network_params"]["seconds_per_slot"] < 12):
 			fail("nimbus can't be run with slot times below 12 seconds")