Drop null_logger (#6013)

* Drop null_logger

Cargo.lock

@@ -780,7 +780,6 @@ dependencies = [
  "bitvec 1.0.1",
  "bls",
  "derivative",
- "environment",
  "eth1",
  "eth2",
  "eth2_network_config",
@@ -2473,6 +2472,7 @@ dependencies = [
  "execution_layer",
  "futures",
  "lighthouse_metrics",
+ "logging",
  "merkle_proof",
  "parking_lot 0.12.3",
  "sensitive_url",
@@ -2957,7 +2957,6 @@ dependencies = [
  "arc-swap",
  "builder_client",
  "bytes",
- "environment",
  "eth2",
  "eth2_network_config",
  "ethereum_serde_utils",
@@ -2972,6 +2971,7 @@ dependencies = [
  "kzg",
  "lighthouse_metrics",
  "lighthouse_version",
+ "logging",
  "lru",
  "parking_lot 0.12.3",
  "pretty_reqwest_error",
@@ -3834,7 +3834,6 @@ dependencies = [
  "bs58 0.4.0",
  "bytes",
  "directory",
- "environment",
  "eth1",
  "eth2",
  "ethereum_serde_utils",
@@ -3876,10 +3875,10 @@ name = "http_metrics"
 version = "0.1.0"
 dependencies = [
  "beacon_chain",
- "environment",
  "lighthouse_metrics",
  "lighthouse_network",
  "lighthouse_version",
+ "logging",
  "malloc_utils",
  "reqwest",
  "serde",
@@ -4464,6 +4463,7 @@ dependencies = [
  "serde",
  "serde_json",
  "serde_yaml",
+ "sloggers",
  "snap",
  "state_processing",
  "store",
@@ -9495,6 +9495,7 @@ dependencies = [
  "eth2_keystore",
  "eth2_network_config",
  "futures",
+ "logging",
  "parking_lot 0.12.3",
  "reqwest",
  "serde",