Bump cardano-api to 11.0.0.0
Adapt to the new `Either MakeUnsignedTxError (UnsignedTx ...)` return of `Exp.makeUnsignedTx` (IntersectMBO/cardano-api#1181). Add a TxCmdMakeUnsignedTxError constructor to TxCmdError so the error surfaces with the existing fromEitherCli/firstExceptT idioms, and update the two call sites in EraBased.Transaction.Run. Bump the cardano-haskell-packages index-state and refresh the CHaP nix flake input to pick up cardano-api 11.0.0.0 (IntersectMBO/cardano-haskell-packages#1358).