refactor: Harden DEPLOYMENT_V20 activation

[PastaPastaPasta]

see

dash/src/chainparams.cpp

Lines 588 to 594 in dfe7089

	consensus.vDeployments[Consensus::DEPLOYMENT_V20].bit = 9;
	consensus.vDeployments[Consensus::DEPLOYMENT_V20].nStartTime = 1661990400; // Sep 1st, 2022
	consensus.vDeployments[Consensus::DEPLOYMENT_V20].nTimeout = Consensus::BIP9Deployment::NO_TIMEOUT;
	consensus.vDeployments[Consensus::DEPLOYMENT_V20].nWindowSize = 120;
	consensus.vDeployments[Consensus::DEPLOYMENT_V20].nThresholdStart = 80; // 80% of 100
	consensus.vDeployments[Consensus::DEPLOYMENT_V20].nThresholdMin = 60; // 60% of 100
	consensus.vDeployments[Consensus::DEPLOYMENT_V20].nFalloffCoeff = 5; // this corresponds to 10 periods

; this has been active for a while, we should harden it in next major version

[knst]

Done: #6225