Update protobuf requirement from <5,>=4.21.6 to >=4.21.6,<6

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@v4.22.0-rc1...v5.26.1)

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

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

Author: dependabot[bot]

pyproject.toml

@@ -37,7 +37,7 @@ dependencies = [
   "grpcio-tools >= 1.54.2, < 2",
   "networkx >= 2.8, < 4",
   "numpy >= 1.24.2, < 2",
-  "protobuf >= 4.21.6, < 5",
+  "protobuf >= 4.21.6, < 6",
   "pydantic >= 2.3, < 3",
   "timezonefinder >= 6.2.0, < 7",
   "tqdm >= 4.38.0, < 5",