Upgrade Rust to 1.52.0 (#17096)

* Upgrade Rust to 1.52.0
update nightly_version to newly pushed docker image
fix clippy lint errors
1.52 comes with grcov 0.8.0, include this version to script

* upgrade to Rust 1.52.1

* disabling Serum from downstream projects until it is upgraded to Rust 1.52.1

core/src/consensus.rs

@@ -91,6 +91,8 @@ pub type Stake = u64;
 pub type VotedStakes = HashMap<Slot, Stake>;
 pub type PubkeyVotes = Vec<(Pubkey, Slot)>;
 
+// lint warning "bank_weight is never read"
+#[allow(dead_code)]
 pub(crate) struct ComputedBankState {
     pub voted_stakes: VotedStakes,
     pub total_stake: Stake,