Update protobuf requirement from <=3.20.1 to <4.21.13

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/generate_changelog.py)
- [Commits](https://github.com/protocolbuffers/protobuf/commits)

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

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

Author: dependabot[bot]

requirements-test.txt

@@ -10,5 +10,5 @@ ray[tune]
 torch==1.12.0
 torchmetrics
 torchvision
-protobuf<=3.20.1
+protobuf<4.21.13
 jsonargparse>=4.13.2