Bump com.google.protobuf:protobuf-java in /scheduler/data-flow

Bumps [com.google.protobuf:protobuf-java](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:protobuf-java
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

scheduler/data-flow/build.gradle.kts

@@ -36,7 +36,7 @@ dependencies {
     implementation("io.grpc:grpc-stub:1.63.0")
     implementation("io.grpc:grpc-protobuf:1.63.0")
     runtimeOnly("io.grpc:grpc-netty-shaded:1.63.0")
-    implementation("com.google.protobuf:protobuf-java:3.25.3")
+    implementation("com.google.protobuf:protobuf-java:4.26.1")
     implementation("com.google.protobuf:protobuf-kotlin:3.25.3")
     implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.7.3")
     implementation("com.michael-bull.kotlin-retry:kotlin-retry:2.0.0")