Bump google.golang.org/grpc in the go_modules group

Bumps the go_modules group with 1 update: [google.golang.org/grpc](https://github.com/grpc/grpc-go).


Updates `google.golang.org/grpc` from 1.31.1 to 1.56.3
- [Release notes](https://github.com/grpc/grpc-go/releases)
- [Commits](grpc/grpc-go@v1.31.1...v1.56.3)

---
updated-dependencies:
- dependency-name: google.golang.org/grpc
  dependency-type: direct:production
  dependency-group: go_modules
...

Signed-off-by: dependabot[bot] <[email protected]>

go.mod

@@ -12,26 +12,25 @@ require (
 	github.com/go-logr/logr v0.2.0
 	github.com/go-openapi/spec v0.19.6
 	github.com/gogo/protobuf v1.3.1
-	github.com/golang/protobuf v1.4.2
-	github.com/google/go-cmp v0.5.2
-	github.com/google/uuid v1.1.1
+	github.com/golang/protobuf v1.5.3
+	github.com/google/go-cmp v0.5.9
+	github.com/google/uuid v1.3.0
 	github.com/json-iterator/go v1.1.10
 	github.com/onsi/ginkgo v1.14.0
 	github.com/onsi/gomega v1.10.2
 	github.com/pkg/errors v0.9.1
 	github.com/satori/go.uuid v1.2.0
 	github.com/shiena/ansicolor v0.0.0-20151119151921-a422bbe96644 // indirect
 	github.com/spf13/cobra v1.0.0
-	github.com/stretchr/testify v1.5.1
-	golang.org/dl v0.0.0-20201105230244-7f2637f4aae3 // indirect
-	golang.org/x/net v0.0.0-20200904194848-62affa334b73
-	google.golang.org/grpc v1.31.1
-	google.golang.org/protobuf v1.25.0
+	github.com/stretchr/testify v1.8.3
+	golang.org/x/net v0.9.0
+	google.golang.org/grpc v1.56.3
+	google.golang.org/protobuf v1.30.0
 	istio.io/api v0.0.0-20200715212100-dbf5277541ef
 	istio.io/client-go v0.0.0-20201005161859-d8818315d678
 	istio.io/gogo-genproto v0.0.0-20191029161641-f7d19ec0141d // indirect
 	k8s.io/api v0.18.8
-	k8s.io/apiextensions-apiserver v0.18.8
+	k8s.io/apiextensions-apiserver v0.18.8 // indirect
 	k8s.io/apimachinery v0.18.8
 	k8s.io/client-go v11.0.1-0.20190805182717-6502b5e7b1b5+incompatible
 	k8s.io/klog v1.0.0