fix: platforms is now exposed as a dependency to users

the protoc toolchain creates targets that reference it.

MODULE.bazel

diff --git a/MODULE.bazel b/MODULE.bazel
index bd23402..ff37643 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -10,13 +10,13 @@
 bazel_dep(name = "rules_license", version = "0.0.7")
 bazel_dep(name = "bazel_skylib", version = "1.3.0")
 bazel_dep(name = "bazel_features", version = "1.2.0")
+bazel_dep(name = "platforms", version = "0.0.8")
 
 # Dependencies needed in tests
 bazel_dep(name = "stardoc", version = "0.5.6", dev_dependency = True, repo_name = "io_bazel_stardoc")
 bazel_dep(name = "rules_cc", version = "0.0.1", dev_dependency = True)
 bazel_dep(name = "googletest", version = "1.11.0", dev_dependency = True, repo_name = "com_google_googletest")
 bazel_dep(name = "protobuf", version = "23.1", dev_dependency = True, repo_name = "com_google_protobuf")
-bazel_dep(name = "platforms", version = "0.0.8", dev_dependency = True)
 
 proto = use_extension("//proto:extensions.bzl", "proto")
 proto.protoc(version = "v25.3")