build(deps): bump google.golang.org/grpc

Bumps the linter-testdata group with 1 update in the /pkg/golinters/protogetter/testdata directory: [google.golang.org/grpc](https://github.com/grpc/grpc-go).


Updates `google.golang.org/grpc` 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
  dependency-group: linter-testdata
...

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

Author: dependabot[bot]

pkg/golinters/protogetter/testdata/go.mod

@@ -1,9 +1,10 @@
 module protogetter
 
 go 1.21.0
+toolchain go1.22.9
 
 require (
-	google.golang.org/grpc v1.67.1
+	google.golang.org/grpc v1.68.0
 	google.golang.org/protobuf v1.35.2
 )