Update protobuf requirement from <=4.24.1 to <=4.24.3

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...v4.24.3)

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

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

requirements.txt

@@ -1,6 +1,6 @@
 click
 Flask==2.3.3
-protobuf<=4.24.1
+protobuf<=4.24.3
 gunicorn==21.2.0
 aiohttp
 tiktoken