Bump com.google.protobuf:protoc from 3.25.3 to 4.26.1 in /examples

Bumps [com.google.protobuf:protoc](https://github.com/protocolbuffers/protobuf) from 3.25.3 to 4.26.1.
- [Release notes](https://github.com/protocolbuffers/protobuf/releases)
- [Changelog](https://github.com/protocolbuffers/protobuf/blob/main/protobuf_release.bzl)
- [Commits](https://github.com/protocolbuffers/protobuf/commits)

---
updated-dependencies:
- dependency-name: com.google.protobuf:protoc
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

examples/gradle/libs.versions.toml

@@ -18,7 +18,7 @@ grpc-testing = { group = "io.grpc", name = "grpc-testing", version = "1.62.2" }
 grpc-stub = { group = "io.grpc", name = "grpc-stub", version = "1.62.2" }
 grpc-kotlin-stub = { group = "io.grpc", name = "grpc-kotlin-stub", version = "1.4.1" }
 
-protoc = { group = "com.google.protobuf", name = "protoc", version = "3.25.3" }
+protoc = { group = "com.google.protobuf", name = "protoc", version = "4.26.1" }
 protobuf-kotlin = { group = "com.google.protobuf", name = "protobuf-kotlin", version = "3.25.3" }
 protobuf-kotlin-lite = { group = "com.google.protobuf", name = "protobuf-kotlin-lite", version = "3.25.3" }
 protobuf-java-util = { group = "com.google.protobuf", name = "protobuf-java-util", version = "3.25.3" }