workflow: fix grpc conflict (#29)

diff --git a/python/pyproject.toml b/python/pyproject.toml
index 0fcd7fc..bbd8aaf 100644
--- a/python/pyproject.toml
+++ b/python/pyproject.toml
@@ -7,8 +7,8 @@
     "License :: OSI Approved :: Apache Software License"
 ]
 dependencies = [
-    "grpcio>=1.62.1",
-    "protobuf>=4.22.0"
+    "grpcio==1.62.1",
+    "protobuf==4.24.2"
 ]
 
 [project.urls]
@@ -40,6 +40,6 @@
 reportPrivateUsage = false
 
 [build-system]
-requires = ["flit_core==3.7.1", "grpcio-tools>=1.62.1"]
+requires = ["flit_core==3.7.1", "grpcio-tools==1.62.1"]
 build-backend = "_build.backend"
 backend-path = ["."]