Update discv5 (#3171)

## Issue Addressed

Updates discv5

Pending on
- [x] #3547 
- [x] Alex upgrades his deps

## Proposed Changes

updates discv5 and the enr crate. The only relevant change would be some clear indications of ipv4 usage in lighthouse

## Additional Info

Functionally, this should be equivalent to the prev version.
As draft pending a discv5 release

beacon_node/lighthouse_network/Cargo.toml

@@ -5,7 +5,7 @@ authors = ["Sigma Prime <contact@sigmaprime.io>"]
 edition = "2021"
 
 [dependencies]
-discv5 = { version = "0.1.0-beta.13", features = ["libp2p"] }
+discv5 = { version = "0.1.0", features = ["libp2p"] }
 unsigned-varint = { version = "0.6.0", features = ["codec"] }
 types = { path =  "../../consensus/types" }
 eth2_ssz_types = "0.2.2"
@@ -26,7 +26,7 @@ smallvec = "1.6.1"
 tokio-io-timeout = "1.1.1"
 lru = "0.7.1"
 parking_lot = "0.12.0"
-sha2 = "0.9.1"
+sha2 = "0.10"
 snap = "1.0.1"
 hex = "0.4.2"
 tokio-util = { version = "0.6.2", features = ["codec", "compat", "time"] }