tracking: 1 sol minimum delegation

[2501babe]

#240 changed the stake program minimum delegation to 1 sol. this is however only the first step on our incredible journey

hard reqs:

• test singlepool against 1sol bpf stake: use multiple stake programs in tests single-pool#497 adds multi-program testing, test against 1sol minimum delegation single-pool#502 adds a 1sol binary
• test stakepool against 1sol bpf stake: use bpf stake stake-pool#424 uses a 1sol binary, since fixes are required for 1lamp
• test agave against 1sol bpf stake. when i removed native stake, i left the branches on the 1sol minimum feature gate in place. so when we cut the release build this is probably as simple as changing the feature gate to the new one
• 4.0.0 audit and release. we can tag 5.0.0 before this but obviously we cant do anything with it
• 5.0.0 audit. the next tag will also contain sysvar removal and the split rewrite so this is nontrivial audit is done with no major findings, pdf to upload soon
• comms. validators have greenlit the change. hooray! we need to do some dapp outreach still

soft reqs:

• float removal. since the pr is unmerged and gabe is out for a few months idk if we want to land it now, cut 5.0.0 without it, or wait v5.0.0 will come first
• singlepool DepositSol. we would like to be able to point sub-1sol stakers to an alternative solution. this entails:
  • the instruction itself. this is easy, ReplenishPool was designed specifically so we could attach DepositSol to the same mechanism. we must however do a holistic review. when we did ReplenishPool, like three reviewers signed off on the code, and the code itself was (as far as we know today!) perfect, but it had unfortunate interactions with other things that hadnt changed
  • math rewrite. code is easy, tests are medium
  • require onramp in deposit/withdraw. code is trivial, the mainnet program and latest released rust bindings support this. but we need to reach out to dapps to make sure they are on the latest version of the dependency