Relax grpc to 1.66.2

PiperOrigin-RevId: 721802054

.github/workflows/ci.yml

@@ -50,7 +50,7 @@ jobs:
           sudo apt-get install -y libprotobuf-dev
           python -m pip install --upgrade pip setuptools
           pip install wheel
-          pip install grpcio-tools>=1.70.0
+          pip install grpcio-tools>=1.66.2
           pip install pytest pytest-xdist
           pip wheel -e .
           pip install -e .

requirements.txt

@@ -3,7 +3,7 @@ absl-py>=1.0.0
 numpy>=1.21.5
 protobuf>=3.6
 portpicker>=1.3.1
-grpcio>=1.70.0
-grpcio-tools>=1.70.0
+grpcio>=1.66.2
+grpcio-tools>=1.66.2
 googleapis-common-protos>=1.66.0
 sqlalchemy>=1.4