resolve lint issues

Author: spencerugbo

internal/file/file_manager_service_test.go

@@ -7,8 +7,6 @@ package file
 
 import (
 	"context"
-	"encoding/json"
-	"errors"
 	"fmt"
 	"os"
 	"path"
@@ -24,7 +22,6 @@ import (
 	mpi "github.com/nginx/agent/v3/api/grpc/mpi/v1"
 	"github.com/nginx/agent/v3/api/grpc/mpi/v1/v1fakes"
 	"github.com/nginx/agent/v3/test/helpers"
-	"github.com/nginx/agent/v3/test/protos"
 	"github.com/nginx/agent/v3/test/types"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"