Remove subpar and test using py_binary directly for protoc grpclib tool

python/grpclib/BUILD.bazel

@@ -1,9 +1,8 @@
-load("@subpar//:subpar.bzl", "par_binary")
 load("@rules_proto_grpc_py3_deps//:requirements.bzl", "requirement")
 
 # Create py binary for grpclib plugin
 # Use subpar to bundle plugin for external execution
-par_binary(
+py_binary(
     name = "plugin",
     srcs = ["plugin.py"],
     legacy_create_init = False,
@@ -11,7 +10,6 @@ par_binary(
     python_version = "PY3",
     srcs_version = "PY3",
     visibility = ["//python:__subpackages__"],
-    zip_safe = False,
     deps = [
         "@com_google_protobuf//:protobuf_python",
         requirement("grpclib"),

python/repositories.bzl

@@ -3,9 +3,7 @@
 load(
     "//:repositories.bzl",
     "rules_proto_grpc_repos",
-    "subpar",
 )
 
 def python_repos(**kwargs):  # buildifier: disable=function-docstring
     rules_proto_grpc_repos(**kwargs)
-    subpar(**kwargs)

repositories.bzl

@@ -243,15 +243,6 @@ VERSIONS = {
         "executable": True,
     },
 
-    # Python
-    "subpar": {
-        "type": "github",
-        "org": "google",
-        "repo": "subpar",
-        "ref": "2.0.0",
-        "sha256": "b80297a1b8d38027a86836dbadc22f55dc3ecad56728175381aa6330705ac10f",
-    },
-
     # Ruby
     "bazelruby_rules_ruby": {
         "type": "github",
@@ -615,12 +606,6 @@ def grpc_web_plugin_linux(**kwargs):
 def grpc_web_plugin_windows(**kwargs):
     _generic_dependency("grpc_web_plugin_windows", **kwargs)
 
-#
-# Python
-#
-def subpar(**kwargs):
-    _generic_dependency("subpar", **kwargs)
-
 #
 # Ruby
 #