Bump com.google.protobuf:protoc from 3.25.5 to 4.31.1

Bumps [com.google.protobuf:protoc](https://github.com/protocolbuffers/protobuf) from 3.25.5 to 4.31.1.
- [Release notes](https://github.com/protocolbuffers/protobuf/releases)
- [Changelog](https://github.com/protocolbuffers/protobuf/blob/main/protobuf_release.bzl)
- [Commits](protocolbuffers/protobuf@v3.25.5...v4.31.1)

---
updated-dependencies:
- dependency-name: com.google.protobuf:protoc
  dependency-version: 4.31.1
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

java-spiffe-core/build.gradle

@@ -50,7 +50,7 @@ task integrationTest(type: Test) {
 
 protobuf {
     protoc {
-        artifact = 'com.google.protobuf:protoc:3.25.5'
+        artifact = 'com.google.protobuf:protoc:4.31.1'
     }
     plugins {
         grpc {