chore(lint): modernize Go (#7536)

Use modern Go constructs through the modernize analyzer from the
golang.org/x/tools package.

Signed-off-by: Ville Vesilehto <ville@vesilehto.fi>

plugin/route53/route53_test.go

@@ -75,8 +75,7 @@ func (fakeRoute53) ListResourceRecordSets(_ context.Context, in *route53.ListRes
 }
 
 func TestRoute53(t *testing.T) {
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
+	ctx := t.Context()
 
 	r, err := New(ctx, fakeRoute53{}, map[string][]string{"bad.": {"0987654321"}}, time.Minute)
 	if err != nil {