Update kusama/polkadot bootnodes (#1895)
closes: https://github.com/paritytech/devops/issues/2090 ## Changes 1. Updated the list of bootnodes. 2. Merged the Connect node and bootnode into a single node. 3. Decreased the number of nodes. 4. Updated the DNS name. ## Description The initial 8 bootnodes were planned to be replaced by community bootnodes, the community node was added but we did not bother to reduce the Parity managed bootnodes. Fixing it now.