Temporarily downgrade protobuf (#413)

## Problem

I need to release 5.4 without any breaking dependency changes.

## Solution

Temporarily revert 1d0f046, which introduced a breaking change in
dependencies

## Type of Change

- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- [ ] This change requires a documentation update
- [x] Infrastructure change (CI configs, etc)
- [ ] Non-code change (docs, etc)
- [ ] None of the above: (explain here)

pyproject.toml

@@ -49,7 +49,7 @@ grpcio = [
 ]
 googleapis-common-protos = { version = ">=1.53.0", optional = true }
 lz4 = { version = ">=3.1.3", optional = true }
-protobuf = { version = "^5.28", optional = true }
+protobuf = { version = "^4.25", optional = true }
 protoc-gen-openapiv2 = {version = "^0.0.1", optional = true }
 pinecone-plugin-interface = "^0.0.7"
 pinecone-plugin-inference = "^2.0.0"