`getRatifyEnv` does not account for proposal deposits

The helper testing function `getRatifyEnv` does not take into consideration voting stake that in the RATIFY rule is included from the proposals deposits.

Originally reported by Copilot:
> `getRatifyEnv` now derives `reVotingStakePoolDistr` from `nesPdL` via `toVotingStakePoolDistr`. Since `PoolDistr` no longer includes proposal deposits, this `RatifyEnv` can undercount stake-pool voting stake in tests that create proposals with deposits. Consider deriving the voting pool distribution from the `DRepPulsingState`/`PulsingSnapshot` (or otherwise adding proposal deposits) to match ledger behavior.

_Originally posted by @lehins in [#6054](https://github.com/IntersectMBO/cardano-ledger/pull/6054/changes#r3982596577)_

Start at the getRatifyEnv helper and trace how nesPdL is passed to toVotingStakePoolDistr. Read the DRepPulsingState and PulsingSnapshot handling to compare the helper with ledger behavior. Done means proposal deposits are represented in the stake-pool voting distribution, with tests covering proposals that include deposits.

Written by the indexing model from the issue text.