Update protobuf requirement from <3.21 to <5.27 (#3147)

Updates the requirements on [protobuf](https://github.com/protocolbuffers/protobuf) to permit the latest version.
- [Release notes](https://github.com/protocolbuffers/protobuf/releases)
- [Changelog](https://github.com/protocolbuffers/protobuf/blob/main/protobuf_release.bzl)
- [Commits](protocolbuffers/protobuf@v2.4.1...v5.26.0)

---
updated-dependencies:
- dependency-name: protobuf
  dependency-type: direct:development
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

setup.py

@@ -187,7 +187,7 @@ def package_files(prefix: str, directory: str, extension: str):
 ]
 
 extra_deps['sentencepiece'] = [
-    'protobuf<3.21',
+    'protobuf<5.27',
     'sentencepiece==0.2.0',
 ]