switch to "protoc-gen-grpc-python-prebuilt" for the grpc-python-plugin

First of all, why does this exist at all? See
grpc/grpc#26125

Because of that way back in #10927 we built the plugin and uploaded it
to binaries.pantsbuild.org.  In the intervening time the original
upstream issue is unresolved, but someone did the work to put together
multi-arch CI at
https://github.com/nhurden/protoc-gen-grpc-python-prebuilt This gives
us a more recent version and fills in the missing macos arm64 support.

We could fork and host in the pantsbuild org on GitHub, but given the
rate of change to grpc-python-plugin I don't think that is warranted
right now.

This removes one of the last things the project pays to serve from
binaries.pantsbuild.org

Author: cburroughs

docs/notes/2.31.x.md

@@ -75,6 +75,8 @@ Added a default module mapping for `apache-airflow-client`, which provides the `
 
 Upgraded the default version of `protoc` to v30.2. Python projects should upgrade the `protobuf` Python requirement to a v6.x version. Java projects should upgrade the `protobuf-java` artifact to a 4.x version.
 
+The `grpc-python-plugin` tool now uses an updated `v1.73.1` plugin built from  <https://github.com/nhurden/protoc-gen-grpc-python-prebuilt]. This also brings `macos_arm64` support.
+
 #### Shell
 
 `shell_command` targets are now runnable via the `run` goal and can be used as a "runnable" target by other targets including the `code_quality_tool` target type. The `run_shell_command` target type remains available at the moment. The difference between running a `shell_command` versus a `run_shell_command` target is that `shell_command` targets can be run within the Pants execution sandbox (and outputs captured) while the more limited execution model of the `run_shell_command` target type only supports interactive execution.

src/python/pants/backend/codegen/protobuf/python/grpc_python_plugin.py

@@ -1,27 +1,37 @@
 # Copyright 2020 Pants project contributors (see CONTRIBUTORS.md).
 # Licensed under the Apache License, Version 2.0 (see LICENSE).
 
-from pants.core.util_rules.external_tool import TemplatedExternalTool
+from pants.core.util_rules.external_tool import ExternalTool
+from pants.engine.platform import Platform
 
 
-class GrpcPythonPlugin(TemplatedExternalTool):
+class GrpcPythonPlugin(ExternalTool):
     options_scope = "grpc-python-plugin"
     help = "The gRPC Protobuf plugin for Python."
 
-    default_version = "1.32.0"
+    # https://github.com/nhurden/protoc-gen-grpc-python-prebuilt maintains a
+    # composite versioning strategy with both the grpc plugin version and the
+    # version of "protoc-gen-grpc-python-prebuilt" that built it
+    default_version = "v0.2.0+v1.73.1"
     default_known_versions = [
-        "1.32.0|macos_arm64 |b2db586656463841aa2fd4aab34fb6bd3ef887b522d80e4f2f292146c357f533|6215304",
-        "1.32.0|macos_x86_64|b2db586656463841aa2fd4aab34fb6bd3ef887b522d80e4f2f292146c357f533|6215304",
-        "1.32.0|linux_arm64 |9365e728c603d64735963074340994245d324712344f63557ef3630864dd9f52|5233664",
-        "1.32.0|linux_x86_64|1af99df9bf733c17a75cbe379f3f9d9ff1627d8a8035ea057c3c78575afe1687|4965728",
+        "v0.2.0+v1.73.1|linux_arm64|91da9e959553224a4f3977313b1e0ec45ba966536da28b76041e151bf218502a|13965288",
+        "v0.2.0+v1.73.1|linux_x86_64|72d864bb3832d8f094f3c9add308724565a446cc8a19f041f8752848068b70a1|13197104",
+        "v0.2.0+v1.73.1|macos_arm64|ea26c8b5c1a534fe271b8a2d8a2683f25d75de4d767fbf0b9e78d43a0ea228ce|33011832",
+        "v0.2.0+v1.73.1|macos_x86_64|ea26c8b5c1a534fe271b8a2d8a2683f25d75de4d767fbf0b9e78d43a0ea228ce|33011832",
+        # Old versions from binaries.pantsbuild.org
+        "1.32.0|macos_arm64 |b2db586656463841aa2fd4aab34fb6bd3ef887b522d80e4f2f292146c357f533|6215304|https://binaries.pantsbuild.org/bin/grpc_python_plugin/1.32.0/macos/x86_64/grpc_python_plugin",
+        "1.32.0|macos_x86_64|b2db586656463841aa2fd4aab34fb6bd3ef887b522d80e4f2f292146c357f533|6215304|https://binaries.pantsbuild.org/bin/grpc_python_plugin/1.32.0/macos/x86_64/grpc_python_plugin",
+        "1.32.0|linux_arm64 |9365e728c603d64735963074340994245d324712344f63557ef3630864dd9f52|5233664|https://binaries.pantsbuild.org/bin/grpc_python_plugin/1.32.0/linux/arm64/grpc_python_plugin",
+        "1.32.0|linux_x86_64|1af99df9bf733c17a75cbe379f3f9d9ff1627d8a8035ea057c3c78575afe1687|4965728|https://binaries.pantsbuild.org/bin/grpc_python_plugin/1.32.0/linux/x86_64/grpc_python_plugin",
     ]
-    default_url_template = (
-        "https://binaries.pantsbuild.org/bin/grpc_python_plugin/{version}/"
-        "{platform}/grpc_python_plugin"
-    )
-    default_url_platform_mapping = {
-        "macos_arm64": "macos/x86_64",  # TODO: Build for arm64.
-        "macos_x86_64": "macos/x86_64",
-        "linux_arm64": "linux/arm64",
-        "linux_x86_64": "linux/x86_64",
-    }
+
+    def generate_url(self, plat: Platform) -> str:
+        prebuilt_version, grpc_version = self.version.split("+")
+        plat_str = {
+            "macos_arm64": "macos-universal",
+            "macos_x86_64": "macos-universal",
+            "linux_arm64": "linux-aarch64",
+            "linux_x86_64": "linux-x86_64",
+        }[plat.value]
+
+        return f"https://github.com/nhurden/protoc-gen-grpc-python-prebuilt/releases/download/{prebuilt_version}/protoc-gen-grpc-python-{plat_str}-{grpc_version}"

src/python/pants/backend/codegen/protobuf/python/rules_integration_test.py

@@ -408,6 +408,7 @@ def test_grpclib_plugin(rule_runner: RuleRunner) -> None:
     )
 
 
+@pytest.mark.platform_specific_behavior
 def test_all_plugins(rule_runner: RuleRunner) -> None:
     rule_runner.write_files(
         {