remove duplicated app.Close call (#17619)

Co-authored-by: Facundo Medica <14063057+facundomedica@users.noreply.github.com>
(cherry picked from commit 202c291)

server/start.go

@@ -2,7 +2,6 @@ package server
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"io"
 	"net"
@@ -277,7 +276,7 @@ func startStandAlone(svrCtx *Context, app types.Application, opts StartCmdOption
 		// so we can gracefully stop the ABCI server.
 		<-ctx.Done()
 		svrCtx.Logger.Info("stopping the ABCI server...")
-		return errors.Join(svr.Stop(), app.Close())
+		return svr.Stop()
 	})
 
 	return g.Wait()
@@ -375,7 +374,6 @@ func startCmtNode(
 	cleanupFn = func() {
 		if tmNode != nil && tmNode.IsRunning() {
 			_ = tmNode.Stop()
-			_ = app.Close()
 		}
 	}