fix: remove unnecessary cms typecasting (backport #14054) (#15668)

Co-authored-by: Javier Su <javier.su.weijie@gmail.com>
Co-authored-by: Julien Robert <julien@rbrt.fr>

CHANGELOG.md

@@ -40,6 +40,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 ## Improvements
 
 * [#15448](https://github.com/cosmos/cosmos-sdk/pull/15448) Automatically populate the block timestamp for historical queries. In contexts where the block timestamp is needed for previous states, the timestamp will now be set. Note, when querying against a node it must be re-synced in order to be able to automatically populate the block timestamp. Otherwise, the block timestamp will be populated for heights going forward once upgraded.
+* [#14019](https://github.com/cosmos/cosmos-sdk/issues/14019) Remove the interface casting to allow other implementations of a `CommitMultiStore`.
 
 ## Bug Fixes
 
@@ -171,7 +172,6 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * [#13802](https://github.com/cosmos/cosmos-sdk/pull/13802) Add --output-document flag to the export CLI command to allow writing genesis state to a file.
 * [#13794](https://github.com/cosmos/cosmos-sdk/pull/13794) `types/module.Manager` now supports the
 `cosmossdk.io/core/appmodule.AppModule` API via the new `NewManagerFromMap` constructor.
-* [#14019](https://github.com/cosmos/cosmos-sdk/issues/14019) Remove the interface casting to allow other implementations of a `CommitMultiStore`.
 * [#14175](https://github.com/cosmos/cosmos-sdk/pull/14175) Add `server.DefaultBaseappOptions(appopts)` function to reduce boiler plate in root.go. 
 
 ### State Machine Breaking

baseapp/baseapp.go

@@ -17,7 +17,6 @@ import (
 	codectypes "github.com/cosmos/cosmos-sdk/codec/types"
 	"github.com/cosmos/cosmos-sdk/snapshots"
 	"github.com/cosmos/cosmos-sdk/store"
-	"github.com/cosmos/cosmos-sdk/store/rootmulti"
 	storetypes "github.com/cosmos/cosmos-sdk/store/types"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
@@ -358,11 +357,11 @@ func (app *BaseApp) Init() error {
 	app.setState(runTxModeCheck, emptyHeader)
 	app.Seal()
 
-	rms, ok := app.cms.(*rootmulti.Store)
-	if !ok {
-		return fmt.Errorf("invalid commit multi-store; expected %T, got: %T", &rootmulti.Store{}, app.cms)
+	if app.cms == nil {
+		return errors.New("commit multi-store must not be nil")
 	}
-	return rms.GetPruning().Validate()
+
+	return app.cms.GetPruning().Validate()
 }
 
 func (app *BaseApp) setMinGasPrices(gasPrices sdk.DecCoins) {