Upgrade to Polkadot v0.9.39

[jasl]

https://github.com/paritytech/substrate/compare/polkadot-v0.9.37...polkadot-v0.9.38 https://github.com/paritytech/substrate/compare/polkadot-v0.9.38...polkadot-v0.9.39

https://github.com/paritytech/cumulus/compare/polkadot-v0.9.37...polkadot-v0.9.38 https://github.com/paritytech/cumulus/compare/polkadot-v0.9.38...polkadot-v0.9.39

Note, I significant reduce election parameters to fix

---- __construct_runtime_integrity_test::runtime_integrity_tests stdout ----
thread '__construct_runtime_integrity_test::runtime_integrity_tests' panicked at 'election weight Weight(ref_time: 693678886000, proof_size: 68995033)s (0.6936789) will exceed a 0.5s chain's block weight (Weight { ref_time: 500000000000, proof_size: 5242880 }) (MaxCandidates 1000, MaxVoters 10000, MaxVotesPerVoter 16 -- tweak these parameters)', /Users/jasl/.cargo/git/checkouts/substrate-7e08433d4c370a21/1837f42/frame/elections-phragmen/src/lib.rs:317:13
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace