test(bigquery): address minor test issues (#6202)

in the first, the integration tests running too long came into conflict
with a expiration time that was too short.  lengthened the test
accordingly.

In the second, cleanup some usages of xerrors that can be moved to
errors as we're now no longer supporting older go versions.

bigquery/integration_test.go

@@ -17,6 +17,7 @@ package bigquery
 import (
 	"context"
 	"encoding/json"
+	"errors"
 	"flag"
 	"fmt"
 	"log"
@@ -39,7 +40,6 @@ import (
 	"github.com/google/go-cmp/cmp"
 	"github.com/google/go-cmp/cmp/cmpopts"
 	gax "github.com/googleapis/gax-go/v2"
-	"golang.org/x/xerrors"
 	"google.golang.org/api/googleapi"
 	"google.golang.org/api/iterator"
 	"google.golang.org/api/option"
@@ -216,7 +216,7 @@ func initTestState(client *Client, t time.Time) func() {
 	tableIDs = uid.NewSpace("table", opts)
 	modelIDs = uid.NewSpace("model", opts)
 	routineIDs = uid.NewSpace("routine", opts)
-	testTableExpiration = t.Add(10 * time.Minute).Round(time.Second)
+	testTableExpiration = t.Add(2 * time.Hour).Round(time.Second)
 	// For replayability, seed the random source with t.
 	Seed(t.UnixNano())
 
@@ -866,7 +866,7 @@ func TestIntegration_InsertErrors(t *testing.T) {
 		t.Errorf("Wanted row size error, got successful insert.")
 	}
 	var e1 *googleapi.Error
-	ok := xerrors.As(err, &e1)
+	ok := errors.As(err, &e1)
 	if !ok {
 		t.Errorf("Wanted googleapi.Error, got: %v", err)
 	}
@@ -886,7 +886,7 @@ func TestIntegration_InsertErrors(t *testing.T) {
 		t.Errorf("Wanted error, got successful insert.")
 	}
 	var e2 *googleapi.Error
-	ok = xerrors.As(err, &e2)
+	ok = errors.As(err, &e2)
 	if !ok {
 		t.Errorf("wanted googleapi.Error, got: %v", err)
 	}
@@ -1437,15 +1437,15 @@ func runQueryJob(ctx context.Context, q *Query) (*JobStatistics, *QueryStatistic
 		job, err := q.Run(ctx)
 		if err != nil {
 			var e *googleapi.Error
-			if ok := xerrors.As(err, &e); ok && e.Code < 500 {
+			if ok := errors.As(err, &e); ok && e.Code < 500 {
 				return true, err // fail on 4xx
 			}
 			return false, err
 		}
 		_, err = job.Wait(ctx)
 		if err != nil {
 			var e *googleapi.Error
-			if ok := xerrors.As(err, &e); ok && e.Code < 500 {
+			if ok := errors.As(err, &e); ok && e.Code < 500 {
 				return true, err // fail on 4xx
 			}
 			return false, fmt.Errorf("%q: %v", job.ID(), err)
@@ -2792,7 +2792,7 @@ func (b byCol0) Less(i, j int) bool {
 
 func hasStatusCode(err error, code int) bool {
 	var e *googleapi.Error
-	if ok := xerrors.As(err, &e); ok && e.Code == code {
+	if ok := errors.As(err, &e); ok && e.Code == code {
 		return true
 	}
 	return false