Upgrade to protobuf 29.0-rc2

This obviates all our patches.

PiperOrigin-RevId: 689506991
Change-Id: I245a5e9ad5e1a5f31223fe5c36c8d5b95d5738cc
diff --git a/repositories.bzl b/repositories.bzl
index 46c2af1..7d28956 100644
--- a/repositories.bzl
+++ b/repositories.bzl
@@ -31,11 +31,11 @@
     "blake3",
     "c-ares",
     "com_github_grpc_grpc",
-    # "com_google_protobuf", # for now, this is an archive_override with special treatment. see distdir.bzl
     "googleapis",
     "grpc-java",
     "io_bazel_skydoc",
     "platforms",
+    "protobuf",
     "rules_cc",
     "rules_go",
     "rules_graalvm",