chore(deps): update dependency protobuf to v29 (#1364)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| protobuf | bazel_dep | major | `28.3` -> `29.0` |

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examples/grpc_example/MODULE.bazel

@@ -53,7 +53,7 @@ bazel_dep(name = "rules_proto", version = "7.0.2")
 
 # Gazelle currently needs protobuf to be named com_google_protobuf.
 # If they fix this, we can remove the repo_name argument.
-bazel_dep(name = "protobuf", version = "28.3", repo_name = "com_google_protobuf")
+bazel_dep(name = "protobuf", version = "29.0", repo_name = "com_google_protobuf")
 
 apple_cc_configure = use_extension(
     "@apple_support//crosstool:setup.bzl",

examples/grpc_package_example/MODULE.bazel

@@ -53,7 +53,7 @@ bazel_dep(name = "rules_proto", version = "7.0.2")
 
 # Gazelle currently needs protobuf to be named com_google_protobuf.
 # If they fix this, we can remove the repo_name argument.
-bazel_dep(name = "protobuf", version = "28.3", repo_name = "com_google_protobuf")
+bazel_dep(name = "protobuf", version = "29.0", repo_name = "com_google_protobuf")
 
 apple_cc_configure = use_extension(
     "@apple_support//crosstool:setup.bzl",