Bump google.golang.org/grpc from 1.67.1 to 1.68.0

Bumps [google.golang.org/grpc](https://github.com/grpc/grpc-go) from 1.67.1 to 1.68.0.
- [Release notes](https://github.com/grpc/grpc-go/releases)
- [Commits](grpc/grpc-go@v1.67.1...v1.68.0)

---
updated-dependencies:
- dependency-name: google.golang.org/grpc
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

go.mod

@@ -1,8 +1,7 @@
 module github.com/stackrox/image-prefetcher
 
 go 1.22.0
-
-toolchain go1.22.1
+toolchain go1.22.9
 
 require (
 	github.com/cenkalti/backoff/v4 v4.3.0
@@ -11,7 +10,7 @@ require (
 	github.com/spf13/cobra v1.8.1
 	github.com/spf13/pflag v1.0.5
 	github.com/stretchr/testify v1.10.0
-	google.golang.org/grpc v1.67.1
+	google.golang.org/grpc v1.68.0
 	google.golang.org/protobuf v1.35.2
 	k8s.io/apimachinery v0.31.3
 	k8s.io/cri-api v0.31.3
@@ -25,9 +24,9 @@ require (
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/kr/text v0.2.0 // indirect
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
-	golang.org/x/net v0.28.0 // indirect
-	golang.org/x/sys v0.24.0 // indirect
-	golang.org/x/text v0.17.0 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20240814211410-ddb44dafa142 // indirect
+	golang.org/x/net v0.29.0 // indirect
+	golang.org/x/sys v0.25.0 // indirect
+	golang.org/x/text v0.18.0 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20240903143218-8af14fe29dc1 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )