Revert "Unpin grpcio for Ray Client (#37368)"

[rkooo567]

This reverts commit 61401da.

Why are these changes needed?

Related issue number

Checks

• I've signed off every commit(by using the -s flag, i.e., git commit -s) in this PR.
• I've run scripts/format.sh to lint the changes in this PR.
• I've included any doc changes needed for https://docs.ray.io/en/master/.
  • I've added any new APIs to the API Reference. For example, if I added a
    method in Tune, I've added it in doc/source/tune/api/ under the
    corresponding .rst file.
• I've made sure the tests are passing. Note that there might be a few flaky tests, see the recent failures at https://flakey-tests.ray.io/
• Testing Strategy
  • Unit tests
  • Release tests
  • This PR is not tested :(

[jjyao]

The error introduced by the reverted PR

(22:46:10) INFO: From Testing //python/ray/tests:test_ray_init:
--
  | ==================== Test output for //python/ray/tests:test_ray_init:
  | Traceback (most recent call last):
  | File "/private/var/tmp/_bazel_ec2-user/6ab9ca4bc8b689ed9acff6044745e900/execroot/com_github_ray_project_ray/bazel-out/darwin-opt/bin/python/ray/tests/test_ray_init.runfiles/com_github_ray_project_ray/python/ray/tests/test_ray_init.py", line 6, in <module>
  | import grpc
  | File "/usr/local/opt/miniconda/lib/python3.8/site-packages/grpc/__init__.py", line 22, in <module>
  | from grpc import _compression
  | File "/usr/local/opt/miniconda/lib/python3.8/site-packages/grpc/_compression.py", line 20, in <module>
  | from grpc._cython import cygrpc
  | ImportError: dlopen(/usr/local/opt/miniconda/lib/python3.8/site-packages/grpc/_cython/cygrpc.cpython-38-darwin.so, 2): Symbol not found: _kCFStreamPropertySocketNativeHandle
  | Referenced from: /usr/local/opt/miniconda/lib/python3.8/site-packages/grpc/_cython/cygrpc.cpython-38-darwin.so
  | Expected in: flat namespace
  | in /usr/local/opt/miniconda/lib/python3.8/site-packages/grpc/_cython/cygrpc.cpython-38-darwin.so

[rkooo567]

Looks like I need code owner approval. cc @richardliaw @ericl @edoakes