[bug]: clean up Python gRPC client instructions

[ZZiigguurraatt]

There are some things in the Python gRPC client instructions that were never needed or are no longer needed.

On lines

lnd/docs/grpc/python.md

Lines 20 to 24 in e6efa2e

	3. Install dependencies (googleapis-common-protos is required due to the use of
	google/api/annotations.proto)
	```shell
	lnd $ pip install grpcio grpcio-tools googleapis-common-protos mypy-protobuf
	```

grpcio googleapis-common-protos mypy-protobuf

can be removed. grpcio is automatically installed by grpcio-tools and googleapis-common-protos is not actually needed because google/api/annotations.proto is not actually needed by the Python gRPC client. As mentioned below, --mypy_out=. does not seem to be actually needed, so that removes the need for mypy-protobuf.

Lines

lnd/docs/grpc/python.md

Lines 25 to 29 in e6efa2e

	4. Clone the google api's repository (required due to the use of
	google/api/annotations.proto)
	```shell
	lnd $ git clone https://github.com/googleapis/googleapis.git
	```

can be deleted.

On lines

lnd/docs/grpc/python.md

Line 38 in e1df8e9

lnd $ python -m grpc_tools.protoc --proto_path=googleapis:. --mypy_out=. --python_out=. --grpc_python_out=. lightning.proto

and

lnd/docs/grpc/python.md

Line 56 in e1df8e9

lnd $ python -m grpc_tools.protoc --proto_path=googleapis:. --mypy_out=. --python_out=. --grpc_python_out=. router.proto

--proto_path=googleapis:. can be replaced with --proto_path=.

.

I'm also not sure what --mypy_out=. is for on lines

lnd/docs/grpc/python.md

Line 38 in e1df8e9

lnd $ python -m grpc_tools.protoc --proto_path=googleapis:. --mypy_out=. --python_out=. --grpc_python_out=. lightning.proto

and

lnd/docs/grpc/python.md

Line 56 in e1df8e9

lnd $ python -m grpc_tools.protoc --proto_path=googleapis:. --mypy_out=. --python_out=. --grpc_python_out=. router.proto

It also does not seem to be needed

Also, I'm not a Ruby user, but I'm guessing references to googleapis in

https://github.com/lightningnetwork/lnd/blob/master/docs/grpc/ruby.md

can probably be removed as well.