Remove grpcio constraint from recently added Python examples
It's no longer necessary as the `pulumi` package itself has the constraint.
MODIFY
aws-py-assume-role/assume-role/requirements.txt
aws-py-assume-role/assume-role/requirements.txt
-grpcio>=1.9.1,!=1.30.0
pulumi>=2.0.0,<3.0.0
pulumi-aws>=2.0.0,<3.0.0

MODIFY
aws-py-assume-role/create-role/requirements.txt
aws-py-assume-role/create-role/requirements.txt
-grpcio>=1.9.1,!=1.30.0
pulumi>=2.0.0,<3.0.0
pulumi-aws>=2.0.0,<3.0.0

MODIFY
azure-py-arm-template/requirements.txt
azure-py-arm-template/requirements.txt
-grpcio>=1.9.1,!=1.30.0
pulumi>=2.0.0,<3.0.0
pulumi-azure>=3.0.0,<4.0.0

Remove grpcio constraint from recently added Python examples (#728)

It's no longer necessary as the `pulumi` package itself has the constraint.