fix: fix MaliciousTar test case (#10158)

fixes #9895

Problem was that provisionerd tries to acquire the next job, and races with shutdown, triggering the assert in the handler.  Switches this test case to use the more robust handler.

provisionerd/provisionerd_test.go

@@ -146,27 +146,24 @@ func TestProvisionerd(t *testing.T) {
 		var (
 			completeChan = make(chan struct{})
 			completeOnce sync.Once
+			acq          = newAcquireOne(t, &proto.AcquiredJob{
+				JobId:       "test",
+				Provisioner: "someprovisioner",
+				TemplateSourceArchive: createTar(t, map[string]string{
+					"../../../etc/passwd": "content",
+				}),
+				Type: &proto.AcquiredJob_TemplateImport_{
+					TemplateImport: &proto.AcquiredJob_TemplateImport{
+						Metadata: &sdkproto.Metadata{},
+					},
+				},
+			})
 		)
 
 		closer := createProvisionerd(t, func(ctx context.Context) (proto.DRPCProvisionerDaemonClient, error) {
 			return createProvisionerDaemonClient(t, done, provisionerDaemonTestServer{
-				acquireJobWithCancel: func(stream proto.DRPCProvisionerDaemon_AcquireJobWithCancelStream) error {
-					err := stream.Send(&proto.AcquiredJob{
-						JobId:       "test",
-						Provisioner: "someprovisioner",
-						TemplateSourceArchive: createTar(t, map[string]string{
-							"../../../etc/passwd": "content",
-						}),
-						Type: &proto.AcquiredJob_TemplateImport_{
-							TemplateImport: &proto.AcquiredJob_TemplateImport{
-								Metadata: &sdkproto.Metadata{},
-							},
-						},
-					})
-					assert.NoError(t, err)
-					return nil
-				},
-				updateJob: noopUpdateJob,
+				acquireJobWithCancel: acq.acquireWithCancel,
+				updateJob:            noopUpdateJob,
 				failJob: func(ctx context.Context, job *proto.FailedJob) (*proto.Empty, error) {
 					completeOnce.Do(func() { close(completeChan) })
 					return &proto.Empty{}, nil