Explicitly specify platforms version to use.

Currently we default to rules_proto version which, which is out of date
and missing @platforms//os:fuchsia. This causes any downstream rulesets
that are configuring using this constraint (rules_rust) to fail to
build.

repositories.bzl

@@ -10,6 +10,14 @@ PROTOBUF_VERSION = "21.10"  # When updating, also update protobuf-javascript, JS
 GRPC_VERSION = "1.54.1"  # When updating, also update grpc hash, grpc-java hash, Go repositories.bzl, Ruby requirements and C#/F# requirements
 BUF_VERSION = "v1.9.0"
 VERSIONS = {
+    "platforms": {
+        "type": "http",
+        "urls": [
+            "https://mirror.bazel.build/github.com/bazelbuild/platforms/releases/download/0.0.6/platforms-0.0.6.tar.gz",
+            "https://github.com/bazelbuild/platforms/releases/download/0.0.6/platforms-0.0.6.tar.gz",
+        ],
+        "sha256": "5308fc1d8865406a49427ba24a9ab53087f17f5266a7aabbfc28823f3916e1ca",
+    },
     # Core
     "rules_proto": {
         "type": "github",
@@ -465,6 +473,7 @@ def rules_proto_grpc_repos(**kwargs):
     """Load the rules_proto_grpc common dependencies."""  # buildifier: disable=function-docstring-args
     check_bazel_minimum_version(MINIMUM_BAZEL_VERSION)
 
+    platforms(**kwargs)
     rules_proto(**kwargs)
     rules_python(**kwargs)
     build_bazel_rules_swift(**kwargs)
@@ -475,6 +484,9 @@ def rules_proto_grpc_repos(**kwargs):
     com_github_grpc_grpc(**kwargs)
     external_zlib(**kwargs)
 
+def platforms(**kwargs):
+    _generic_dependency("platforms", **kwargs)
+
 def rules_proto(**kwargs):
     _generic_dependency("rules_proto", **kwargs)