Update Python proto library to latest

[cretz]

Is your feature request related to a problem? Please describe.

Currently we're on 3.x because grpcio package which we support as optional requires 3.x. But Pulumi seems to allow both: https://github.com/pulumi/pulumi/blob/master/sdk/python/requirements.txt. See if we can too. There is also (intentionally unlinked) PR 30382 on https://github.com/grpc/grpc that may let us upgrade.

[brightsparc]

Note the gRPC version that this library currently targets is ^1.48.0 however there is a known memory leak for >=1.43.0 so suggest until this has been resolved pinning the gRPC dependency to 1.41.0 which is know to be stable.

[bergundy]

We don't invoke grpc directly from Python, it all goes through Rust Core using tonic so I this memory leak probably doesn't apply to this SDK.