fix: increase minimum protobuf version to 6.31.1

Author: khneal

packages/pynumaflow/pyproject.toml

@@ -28,7 +28,7 @@ grpcio = "^1.48.1"
 grpcio-tools = "^1.48.1"
 google-api-core = "^2.11.0"
 grpcio-status = "^1.48.1"
-protobuf = ">=3.20,<7.0"
+protobuf = ">=6.31.1,<7.0"
 aiorun = "^2023.7"
 uvloop = ">=0.21.0"
 psutil = "^6.0.0"