fix: re-create viper instance to get env vars and correct home (#1207)

- ~Update cosmos-sdk ref `e1b8b82c712b491ab95d4a605e8432b9df310032`~
- ~Update cometbls ref `5b33e3460932083218073f498bc9a15d68e17629`~
- Apply fix from cosmos/cosmos-sdk#18994 to
`uniond/cmd/uniond/cmd/root.go`

**Scope updated**: only apply root.go fix. Other changes to be handled
in #1199

uniond/cmd/uniond/cmd/root.go

@@ -99,7 +99,7 @@ func NewRootCmd() (*cobra.Command, appparams.EncodingConfig) {
 			cmd.SetOut(cmd.OutOrStdout())
 			cmd.SetErr(cmd.ErrOrStderr())
 
-			initClientCtx = initClientCtx.WithCmdContext(cmd.Context())
+			initClientCtx = initClientCtx.WithCmdContext(cmd.Context()).WithViper("")
 
 			initClientCtx, err := client.ReadPersistentCommandFlags(initClientCtx, cmd.Flags())
 			if err != nil {